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22 DICAS TÉCNICAS PARA MANTER A MOTA A ANDAR FORTE!  Inserido Wednesday 11 June 2008 23:25

With Pro Circuit's Dave Chase

 

 

 

Today's bikes aren't cheap, so getting your money's worth out of your bike is critical to your enjoyment of the sport. It's possible to offset the cost of riding and greatly extend the life of your bike if you keep up the necessary routine maintenance. There are many little chores that are easily neglected; such things as lubing the cables after you wash your bike or tightening the spokes properly can allow your bike to not only last longer but to operate better. Some of these tech tips may seem simple, but we feel these seven areas are often overlooked—and have the most potential to save you money in the long run. So we caught up with Pro Circuit's ace wrench Dave Chase and asked him about routine maintenance.

Chase is an experienced mechanic and fabricator, with off-road and motocross credentials. Plus, earlier in his career he earned the SCORE No. 1 plate by making fragile Husqvarnas survive distance races. He's worked with budgets of all sizes, so he was the ideal source for information. Here's what he said about exhaust-pipe maintenance, carburetor care, spoke maintenance and tightening procedures, proper chain treatment, the cleaning and lubing of cables, diagnosing reed-petal problems and doing a "quick fix" at the track should you break or crack plastic parts on your bike.

Cleaning and Lubing Cables

 

 

Lubing your cables is one of the cheapest ways to keep your bike feeling new. Water and dirt seep into your cables when you wash the bike. Using a pressure washer is even more of a problem. Cleaning and lubing your cables not only eliminates the water and dirt but also increases the cable's life. To clean and lube your cables, you have to remove the cable from the perch and lever. For throttle cables you must disconnect the carburetor end; you don't want to flush water and dirt into the carburetor. Put on a standard cable lube tool and flush the cable with contact cleaner. The contact cleaner will cleanse any dirt and grime in its path. Then flush the cable several times with a lubricant.

About every third time you lube the cable, reassemble the lever with some light grease around the pivot hole. The light grease will give the lever a smoother feel and reduce the effort required to operate it. The grease will also attract grit, so you will need to clean the lever and perch more often than if you leave it dry.


You must remove the cable from the control end (both ends on the throttle cable) to lube it.
You must remove the cable from the control end (both ends on the throttle cable) to lube it.		 Motion Pro and some of the manufacturers sell these little cable pressure devices
Motion Pro and some of the manufacturers sell these little cable pressure devices		 The lube tool is sealed with rubber, but the spray will leak, so use a rag to save the mess.
The lube tool is sealed with rubber, but the spray will leak, so use a rag to save the mess.

Pipe Maintenance

 

Plated pipes can be cleaned with any bike washing product, but raw steel pipes need Scotch-Brite.
Plated pipes can be cleaned with any bike washing product, but raw steel pipes need Scotch-Brite.

 

When installing your exhaust system, you should remember the seal between the cylinder and the exhaust spigot is crucial to your bike's performance. On a two-stroke, whenever you remove the pipe, the rubber O-ring (or crush gasket on some Hondas) should always be inspected for any cracks or blemishes. Even if it just has a flattened look to the outside, replace it. Some bikes have a thin metal ring that goes into the exhaust port to prevent the steel pipe from damaging the aluminum surface the pipe butts up against. Make sure this ring is still in place and in good condition. If new O-rings don't make a tight fit, you may need to use a thin coat of high-temp silicone to get a secure seal.

Install all pipe springs before you bolt the exhaust into place. This will allow the pipe to get the best seal with no binding. Installing the springs first will allow the somewhat-delicate vibration-canceling rubber mounts to do their job without being torn in half. After every wash, scrub the entire surface of bare steel pipes with a Scotch-Brite pad and some cleaner. Scrubbing will rid your pipe of any corrosion and make it look new again.

If you have a four-stroke, you should always wipe down the header with a Scotch-Brite pad. Keeping the surface looking like new will ultimately make it last longer.


Cleaning a four-stroke header will prolong the life of the part and keep it looking nice.
Cleaning a four-stroke header will prolong the life of the part and keep it looking nice.		 Keep the O-rings or gasket that seal the pipe to the cylinder joint fresh and tight for best performance.
Keep the O-rings or gasket that seal the pipe to the cylinder joint fresh and tight for best performance.		 Exhaust pipe springs should be kept new and tight as well. They age like any other part.
Exhaust pipe springs should be kept new and tight as well. They age like any other part.

Chain and Sprocket Care

The key to good chain life is always having your chain adjusted properly and keeping it lubed. Whenever you install a new chain, you must replace the sprockets. When you have a new chain and new sprockets, they wear together. Replacing the whole drivetrain also allows you to get the most out of your chain and sprockets. Putting a new chain on a worn-out sprocket will wear out the chain immediately. Similarly, a worn chain will ruin new sprockets. For all but the most-serious 125cc-class racers, replacing the standard chain with an O-ring chain will save a great deal of money. An O-ring chain lasts much longer, so it doesn't wear out sprockets as quickly.

Whenever you install a new chain, make sure the master-link clip opening is facing the opposite way of the travel, so there is no chance of the clip hitting something and getting knocked off. If you ride in any mud, watch to see that the master-link clip doesn't get worn. The clip can wear so thin it breaks! Always make sure your chain is adjusted correctly and is lubed every time you head to the track. The best time to lube your chain at the track is right after you pull off. When the chain is still hot, it will allow the lube to flow inside the rollers and pins where it is needed most.


Make sure that the closed end of the master link clip faces forward so it doesn't get knocked off.
Make sure that the closed end of the master link clip faces forward so it doesn't get knocked off.		 The sprocket bolts must be tight or the hub will be ruined. Many mechanics suggest using new bolts.
The sprocket bolts must be tight or the hub will be ruined. Many mechanics suggest using new bolts.

Spoke Maintenence and Tightening

 

 

There is a definite science to tightening spokes; you can't just crank them tight with a spoke wrench and call it good. When tightening spokes, always space out the tightening, skipping five spokes at a time. It will take about seven wheel rotations to tighten every spoke. Skipping those five spokes allows them to be tightened evenly; you won't be pulling one side of the wheel more than the other.

When tightening, go a quarter turn at a time with your spoke wrench to avoid pulling the wheel out of true. If any spokes are loose but the nipples are hard to turn, give them a drop of assembly lube or motor oil so they turn with more ease.


You can buy this small lube bottle at a hardware store. Aerosols are too much for this job.
You can buy this small lube bottle at a hardware store. Aerosols are too much for this job.		 A small amount of lubrication (light motor oil) will keep the nipples from corroding to the spokes.
A small amount of lubrication (light motor oil) will keep the nipples from corroding to the spokes.		 Use a spoke wrench with a snug fit on the nipple, and tighten a little at a time.
Use a spoke wrench with a snug fit on the nipple, and tighten a little at a time.

Carburetor Care and Maintenance

 

 

Four-stroke and two-stroke carburetors are very similar in that they both require general maintenance on occasion. If the bike sits for a while, gas will evaporate and leave a dry, powdery or sticky buildup in the carburetor. The residue may plug all the jets, but almost certainly it will block the pilot jet. Ideally, you should drain the float bowl after riding and store your bike with its fuel petcock turned off. If you fail to take those steps, it's important to disassemble the carburetor if your motorcycle hasn't been ridden in a while. Some of today's fuels can go bad in just a month.

On four-strokes you also have to take apart and lube the hot-start cable just as you do with all your other cables. When you wash your bike, water runs down the cable, gets into the hot-start mechanism and causes corrosion in the carburetor. If the hot-start mechanism corrodes badly, it could demand a new carburetor body.

Check your float level based on what the owner's manual says. The floats can come out of adjustment over time and with extreme use. The carburetor is the heart of your bike, and it should be serviced and cleaned on a regular basis.


Use a Phillps screwdriver with a good tip that fits the carburetor float bowl screws well.
Use a Phillps screwdriver with a good tip that fits the carburetor float bowl screws well.		 Clean inside the float bowl, then disassemble and clean the accelerator pump on the bowl's bottom.
Clean inside the float bowl, then disassemble and clean the accelerator pump on the bowl's bottom.		 You adjust the float level by bending the small tang that depresses the float needle valve.
You adjust the float level by bending the small tang that depresses the float needle valve.

Emergency Plastic Repairs

 

Drill small, paired holes along both sides of the crack that needs repair.
Drill small, paired holes along both sides of the crack that needs repair.

 

If you break a fender or a shroud while at the track, there are quick and dirty ways to repair the crack or break so you can finish your ride. You can stitch up your plastic just as a doctor would stitch up a cut. Just drill a few holes on both sides of the crack and run a few zip-ties across. Also, you must drill a hole at the end of the crack so the crack doesn't continue. Don't space the holes more than 1/2 inch apart. It may not be the prettiest way of repairing your bike, but when you're out at the track, it's an easy fix and it really works!


Make sure there are sufficient holes for the repair to have strength.
Make sure there are sufficient holes for the repair to have strength.		 Use plastic zip-ties or safety wire to
Use plastic zip-ties or safety wire to "sew" the repair together.		 The temporary repair isn't pretty but it amazingly effective.
The temporary repair isn't pretty but it amazingly effective.

Reed Maintenance

 

 

When your bike becomes hard to start or won't carburet cleanly at small throttle openings, you should begin to suspect your bike has a reed problem. When you pull out the reed cage, look at the outer corners of the reed petals. Usually, the first area to wear is the outer corners, which will chip or fray. Any chipping or fraying will keep the reed from sealing completely. Whenever you see any damage or wear to the reed edges, you must replace the reed petals. Simply remove the screws that hold the petal in place and install a new one. Use a quality screwdriver, since the screws are often sealed in place with a thread-locking compound. Plus, the heads are tiny, and you don't want to risk stripping them. When you install the new petal, make sure it is indexed properly. Simply match it up with the shape of the cage and the petal stop. When you screw the petal back into place, be sure to use a thread-locking agent on the screws so they have no chance of backing out; digesting a reed-petal screw is bad news for a two-stroke engine. Also, make sure you use a fresh gasket (if any) when you put the reed cage back in the motor.


Reeds usually install only one way. Note that one corner is round and the other angled.
Reeds usually install only one way. Note that one corner is round and the other angled.		 Reeds tend to show wear at the tips and front corners. They can fray or even chip.
Reeds tend to show wear at the tips and front corners. They can fray or even chip.		 Use Loctite on the screws that hold the reeds to the cage. The engine won't like digesting one.
Use Loctite on the screws that hold the reeds to the cage. The engine won't like digesting one.
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Manutenção Motor - YZ250  Inserido Tuesday 20 May 2008 23:25

Yamaha's YZ250F has existed for more years than any of the other 250cc four-strokes, so it is less of a mystery—one reason we left it for last in our series on small-bore four-strokes. The other reason is the Yamaha has fewer weaknesses to pinpoint. In fact, we had FMF Racing's Dave Dye show us the intricacies of the engine, and he felt it really had no Achilles' heel. Most recently Dye wrenched for Chad Reed for both the Yamaha factory team and during his stint with Yamaha of Troy, but before that he wrenched for Steve Lamson, Tim Ferry and Brian Swink. However, a race team such as YoT routinely changes valves, pistons and cam chains, so they may never see problems that an average owner—who leaves those same parts in play much longer—might encounter.

 

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For expertise on engines that have been subjected to typical weekend-warrior abuse and maintenance, we turned to Thumper Racing. The company warned that the cam chain may be a weak point. Thumper recommends changing the cam chain twice a year and the valves once a year for a YZ250F that is ridden hard. The cam chain is less than $20 and is extremely easy to change any time you are checking valve clearance.

As with any of the new-generation small four-strokes, we were impressed with the minimal amount of effort required to perform a top end rebuild.

1. To get started, drain the coolant and the oil, remove the exhaust pipe and header and get any parts that keep you away from the motor out of your way. Remove the spark plug so it is easier to turn the engine over.

 

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2. Dye also removed the carburetor to make working on the head easier and provide more room to get hands and tools in place.

3. You'll need to move the clutch cable since it is blocking access to the cylinder. The more room you can give yourself to work, the better. Dye used pliers to move the actuating arm and get enough slack in the cable.

4. Now the engine is ready for us to begin. The head stay is removed, the oil breather hoses are disconnected, the carb is removed and the coolant hoses are disconnected. (It isn't necessary to completely remove the radiators, but we did so to make photography easier.)

 

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5. Pull the cam cover. Dye used a 3/8-inch-drive T-handle with an Allen socket. A T-type Allen wrench with a ball end works well, too.

 

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6. Remove the plugs in the ignition cover to rotate the crankshaft and line up the timing mark on the ignition rotor with the indicator on the ignition cover. The hole is small, so a compact flashlight helped us see what we were doing.

7. When the timing marks are lined up, the lobes on the intake cam should face to the rear, the exhaust cam lobes should point forward and the dots on the cam sprockets (two on the intake cam and one on the exhaust cam) should line up with the head's upper gasket surface. The pointer shows the rearmost dot, but you can also see the one on the other side of the intake cam sprocket.

8. Pull the bolt out of the back of the cam-chain tensioner. Insert a small-blade screwdriver into the bolt hole and roll the cam-chain tensioner back in by gently turning it clockwise until it locks. That will take the tension off the cam chain. We find it easier to simply remove the tensioner to get the maximum play in the chain.

 

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9. Pull out the small bolts that hold the cam bearing caps. Then hold the bearing caps at the bottom and carefully work them loose.

10. As on the other 250cc four-stroke motocross engines, there are locating clips in the cams that you don't want to drop down in the engine. Lift the cams slowly, and watch for the clips as you go.

11. Lift the cam so the right side is a little higher and the sprocket drops down into the cam-chain channel, then pull the cam chain away from the sprocket and lift out the intake cam followed by the exhaust cam. We are changing the cam chain, so we just dropped the chain down in the cam-chain passage.

 

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12. Remove the head bolts. The YZ has long bolts that hold down the head and cylinder. Pull them out. The bolts have washers under them, but the oil in the head will hold them until after the head is off. It is safer to leave them in place than try to pull them out and risk dropping them into the engine.

13. Remove the bolt that holds the oil line to the head. There is a crush washer on each side of the fitting. One will come off with the bolt, but the other can fall out and get lost if you don't watch for it. Both washers should be replaced. They are designed to be used only once.

14. You will also need to remove these two small bolts that seal the head to the cylinder on the cam-chain side. You must use a wrench; a socket won't fit.

15. Pull off the head, but use care so you don't knock any of the gasket surfaces into the frame tubes. Check the location of the dowel sleeves that are in the head and the cylinder.

 

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16. We sprayed contact cleaner into the ports to see if the valves were still sealing properly. The YZ250F had a full 18 months of use before our rebuild. Nevertheless, the valves were sealing perfectly. We cleaned up the gasket surface with a Scotch-Brite pad but made sure not to touch the surface of the valves.

17. Then we put the cams back in the head in the proper place, replaced the cam-bearing caps and torqued the caps to the proper specs from the manual.

18. We checked the valve clearances with the head on the workbench using Motion Pro feeler gauges. These gauges have a solid handle with a prebent feeler-gauge tip and are extremely easy to work with. The YZ250F should have 0.13mm clearance on the intakes and 0.20mm on the exhaust side. All five valves still had perfect clearance, so we felt confident assembling the engine without doing anything more to the valves.

 

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19. Before the cylinder can be removed, this bolt must be removed from the cam-chain side of the cylinder. Then the cylinder should come up easily.

20. The YZ uses a snap ring in the piston pin instead of circlips, so use snap-ring pliers to remove the rings. Then pull the piston pin and remove the piston. Stuff the cases with a clean rag to prevent losing the clip.

21. Before the ignition cover can come off, the shift lever needs to be removed.

 

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22. Next we pulled the ignition cover to start the cam-chain replacement. This is one reason we drained the oil before starting the job.

23. Use an impact-driver to get the center retaining bolt out, then use a Motion Pro or Yamaha ignition puller to remove the rotor.

24. Pull out the stator plate with a T30 Torx bit then pull it aside. The plate can go in only one way, so don't worry about marking the location.

 

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25. Remove the rear cam-chain tensioner by removing the two bolts at the bottom. Next slide the tensioner down and wiggle it out through the bottom.

26. Clean up the gasket surfaces on the cylinder, cases and head. Remove the gasket pieces, and clean the surface with a Scotch-Brite pad. After all the parts are clean, organize them and get them ready for assembly.

27. Install one of the snap rings in the piston pin, then oil and install the piston pin partway.

28. Install the piston rings as directed in the manual. We used a Wiseco piston, and it came with its own instructions for the ring gaps, but they are essentially the same as the manual suggests. The important thing is the ring gaps are all at different spots. Put a little four-stroke oil on the piston and rings.

 

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29. Install the piston on the connecting rod, and insert the other snap ring. Again, it is safest to cover the opening to the cases with a rag, unlike this photo.

 

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30. Take care with the rings as they go into the cylinder. They need to be compressed with your fingers before you attempt to slide the cylinder over. The side rails of the oil ring are very thin and can snag and be damaged very easily. With the engine in the bike, we found it easier to install the piston into the cylinder while it was on the bench. We slid the piston in just slightly, so the rings were fully inside the bore but the pin boss was still fully exposed below the cylinder.

31. Then we installed the base gasket, slid the piston and cylinder down, and installed the piston pin and second clip before easing the cylinder down. In addition to the new gasket, there is an O-ring around the dowel for the water passage at the front right corner of the cylinder.

 

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32. Drop the new cam chain down through the cylinder into the crankcase. Slip it over the end of the crank, and get the chain on the sprocket. Slide the cam-chain guide up through the cylinder and bolt it in.

33. The stator goes in only one way, so position it, slip in the Torx bolts and snug it down.

34. Impact the rotor on while holding the cam chain tight to secure the engine.

35. Install the ignition cover after setting the ignition back at the correct timing mark.

 

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36. Slip the front cam-chain slide into the cylinder. Make sure the bottom tip is seated in the notch in the cases it is supposed to sit in. When it is located correctly, the nubs on the side of the slide will be below the surface of the cylinder. Install the new cylinder head gasket and the dowel collars in the top of the cylinder.

37. We removed the cams and cam-bearing caps then installed the head back onto the cylinder. Hold the cam chain up while the head is sliding down.

38. Install the head bolts. Don't forget the washers. Torque the head bolts in two steps: First, torque them all to 14 foot-pounds; second, torque them to 27 foot-pounds to finish up.

39. Put the oil line back on with new crush washers (one on each side of the fitting).

 

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40. Dye finds it easiest to install the exhaust cam first. Make sure the crank is still set on the correct mark and install the cam. The exhaust cam has two dots on it. One is straight up; the other aligns with the machined edge of the head at the front of the engine. With the dots lined up, pull the cam chain across then install the cam-bearing caps and torque them to 7 foot-pounds or 84 inch-pounds in a crisscross pattern.

41. Install the intake cam next. Again, line up its three dots; two with the machined surface of the head, and one pointed straight up. When the cams are in correctly, there should be 12 pins in the cam chain between the top dots on both cams.

42. Release the cam-chain tensioner and install the bolt in the rear. Recheck that all the timing marks are lined up before installing the plugs in the ignition cover.

43. Install the cam cover and reassemble the bike.

 

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44. You're now ready for that break-in ride!

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Troque os retentores da suspensão dianteira em 30 min.  Inserido Wednesday 30 April 2008 23:14

Blogue de aventura : Moto TT, tudo o que precisa saber, Troque os retentores da suspensão dianteira em 30 min.

Modern dirt bikes have big, beefy forks with comparatively massive inner steel tubes to handle the rigors of current track and trail obstacles. The combination of inverted design and 47-50mm inner tubes solve any flex problems, but they bring their own headaches. For one, when you get big tubes, there is the problem of seal drag, so manufacturers are always treading a fine line between seal life and seal drag. For another, with the inverted design, the seal is trying to hold in oil sitting above it, rather than under it. Making this more difficult, the backs of the steel inner tubes are exposed to debris thrown by the front tire and the lips inside the seal that actually hold back the oil are delicate and easily cut by nicks in the tubes.

A full rebuild of late-model KYB and Showa sealed-cartridge forks requires a variety of special tools, but all the seal does is keep the oil in the outer chamber. If you need just a seal change and not a full servicing, the job can be a lot easier. We looked at ways to do the seal swap with a minimum of special tools, time and mess and found you can accomplish the job with normal hand tools, a vise with soft jaws, a Ratio Rite and a seal slammer. If you have a helper to hold the fork upright, you won't need a vise. We managed the replacement without even taking off the top of the fork. We did the job in an ordinary garage, with moto-kid Chris Dvoracek doing his first-ever fork seal change.

 

Before you start, clean up the bench and organize your tools. If you plan on doing your own suspension regularly, a suspension vise like this one from Park Tool (www.parktool.com; 651/777-6868) is an awesome addition to a garage. If you mount it so it extends over the edge of the bench, you can also use it to work on bicycles. For a racer like Dvoracek, that is a bonus. You'll need some contact cleaner, fork oil (of the correct weight for your brand of fork) and shop-type paper towels.
Before you start, clean up the bench and organize your tools. If you plan on doing your own suspension regularly, a suspension vise like this one from Park Tool (www.parktool.com; 651/777-6868) is an awesome addition to a garage. If you mount it so it extends over the edge of the bench, you can also use it to work on bicycles. For a racer like Dvoracek, that is a bonus. You'll need some contact cleaner, fork oil (of the correct weight for your brand of fork) and shop-type paper towels.		 One of the main reasons you need a special suspension vise or a normal bench vise with soft jaws is to hold the leg while you release the cartridge rod nut in the bottom of the fork leg. The solution is to crack the nut loose while the fork is still on the bike. If you just unfasten it, no oil will come out. Just make sure the ratchet is set to loosen. It is easy to get confused when working upside down.
One of the main reasons you need a special suspension vise or a normal bench vise with soft jaws is to hold the leg while you release the cartridge rod nut in the bottom of the fork leg. The solution is to crack the nut loose while the fork is still on the bike. If you just unfasten it, no oil will come out. Just make sure the ratchet is set to loosen. It is easy to get confused when working upside down.		 You will need a vise with soft jaws made from copper, aluminum or plastic. We found these magnetic plastic units at a Lowe's for less than eight bucks. Or get a helper to hold the fork upright and forget the vise. Simply put a wood, cardboard or rubber mat under the cap so it doesn't get damaged.
You will need a vise with soft jaws made from copper, aluminum or plastic. We found these magnetic plastic units at a Lowe's for less than eight bucks. Or get a helper to hold the fork upright and forget the vise. Simply put a wood, cardboard or rubber mat under the cap so it doesn't get damaged.
Since the seal was leaking, the areas near the wiper and the axle holder were covered in oil and dirt. Wipe off the fork before proceeding. Clean the area around the bolt head well. You will be working with the fork upright, and any stray dirt will end up inside the fork. Before you proceed, turn the adjuster all the way in while counting the clicks. Record the setting and then turn the adjuster all the way out.
Since the seal was leaking, the areas near the wiper and the axle holder were covered in oil and dirt. Wipe off the fork before proceeding. Clean the area around the bolt head well. You will be working with the fork upright, and any stray dirt will end up inside the fork. Before you proceed, turn the adjuster all the way in while counting the clicks. Record the setting and then turn the adjuster all the way out.		 With the fork secured, loosen the base bolt. If you didn't slacken the base bolt while the fork was on the bike, use the front axle to hold the fork while you free it up. Unthread the bolt until it is out of the axle holder.
With the fork secured, loosen the base bolt. If you didn't slacken the base bolt while the fork was on the bike, use the front axle to hold the fork while you free it up. Unthread the bolt until it is out of the axle holder.		 This step is easier with a special tool from Race Tools (www.racetools.com; 585/328-9160), Motion Pro (www.motionpro.com; 650/594-9600) or Race Tech (www.race-tech.com; 951/279-6655). The manual that comes with the bike provides the dimensions to make a tool as well. It is possible to use a 12mm wrench. With one hand, pull down firmly on the inner (steel) fork tube. You need to pull it down far enough to get a tool or a wrench jammed under the lock nut, as shown here.
This step is easier with a special tool from Race Tools (www.racetools.com; 585/328-9160), Motion Pro (www.motionpro.com; 650/594-9600) or Race Tech (www.race-tech.com; 951/279-6655). The manual that comes with the bike provides the dimensions to make a tool as well. It is possible to use a 12mm wrench. With one hand, pull down firmly on the inner (steel) fork tube. You need to pull it down far enough to get a tool or a wrench jammed under the lock nut, as shown here.
Use a wrench to hold the lock nut and a wrench or a socket to break loose the base nut from the lock nut. Then fully unthread the base bolt from the cartridge rod. Clean the base bolt and set it aside.
Use a wrench to hold the lock nut and a wrench or a socket to break loose the base nut from the lock nut. Then fully unthread the base bolt from the cartridge rod. Clean the base bolt and set it aside.		 The rebound adjuster in the base bolt compresses this rod. It is easiest to remove it now, so it doesn't drop out when you dump the oil. Set it aside as well. The work bench we were on is well used, so we laid out paper towels to keep the parts clean. Finally, pull down the fork tube and release the holding tool.
The rebound adjuster in the base bolt compresses this rod. It is easiest to remove it now, so it doesn't drop out when you dump the oil. Set it aside as well. The work bench we were on is well used, so we laid out paper towels to keep the parts clean. Finally, pull down the fork tube and release the holding tool.		 Use a blade screwdriver to pry up the fork wiper. It should come up easily after you work the tip in between the wiper and the outer tube.
Use a blade screwdriver to pry up the fork wiper. It should come up easily after you work the tip in between the wiper and the outer tube.
A wavy snap ring keeps the seal and Teflon-impregnated bushings in place. It is simple to reach in with a small screwdriver and pop out the snap ring. Be careful so you don't mark the tube with the screwdriver tip.
A wavy snap ring keeps the seal and Teflon-impregnated bushings in place. It is simple to reach in with a small screwdriver and pop out the snap ring. Be careful so you don't mark the tube with the screwdriver tip.		 Grab the inner and outer tubes firmly, one in each hand. With the fork upright (to keep the mess to a minimum), compress, then rapidly extend the inner fork tube. You use the inner tube like a slide-hammer to pop out the bushings and seal. The seal and bushing will usually pop loose rather suddenly, so be careful.
Grab the inner and outer tubes firmly, one in each hand. With the fork upright (to keep the mess to a minimum), compress, then rapidly extend the inner fork tube. You use the inner tube like a slide-hammer to pop out the bushings and seal. The seal and bushing will usually pop loose rather suddenly, so be careful.		 Lay out the parts on your paper towels until you are ready for them. Slide out the spring and lay it down. Some forks have springs that need to go in a specific direction. Check the ends of the springs. Most have lines ground in to one end to identify them. This fork has the springs in with the ground marks down. Prop up the outer fork tube so the oil doesn't dump out yet.
Lay out the parts on your paper towels until you are ready for them. Slide out the spring and lay it down. Some forks have springs that need to go in a specific direction. Check the ends of the springs. Most have lines ground in to one end to identify them. This fork has the springs in with the ground marks down. Prop up the outer fork tube so the oil doesn't dump out yet.

 

 

 

Use your thumbnails to pry apart the first bushing. It is usually pretty easy, and when spread just a bit, it will easily slip off the end of the fork tube. The cleaned bushing should be uniformly gray on the outside. If the underlying brass is showing through at any point, look for damage inside the outer fork tube. Your quick and dirty fork seal change is over, and you'll need additional special tools.
Use your thumbnails to pry apart the first bushing. It is usually pretty easy, and when spread just a bit, it will easily slip off the end of the fork tube. The cleaned bushing should be uniformly gray on the outside. If the underlying brass is showing through at any point, look for damage inside the outer fork tube. Your quick and dirty fork seal change is over, and you'll need additional special tools.		 The rest of the parts slide right off. Lay them out in the order they come off. The washer that goes between the seal and the bushing isn't too critical for this Showa, but a Kayaba has a machined part that must go in the way it comes out. The second bushing should have the uniformly gray color inside. If the brass shows through in streaks, look for significant damage in the steel inner tube's surface.
The rest of the parts slide right off. Lay them out in the order they come off. The washer that goes between the seal and the bushing isn't too critical for this Showa, but a Kayaba has a machined part that must go in the way it comes out. The second bushing should have the uniformly gray color inside. If the brass shows through in streaks, look for significant damage in the steel inner tube's surface.		 Clean the tube extremely well, then under good light, inspect it for nicks that may have cut the seal. Use a razor blade to judge any imperfections you see. If the razor catches on any small pits, they will need to be dressed and have the edges removed before the new seal is put in. Nicks will almost always be at the back of the fork tube. Deep or large scrapes or gouges may not be repaired successfully. To keep the fork light, the outer tubes are very thin, and they can be dented right through fork guards in a crash involving another machine. The inner tube must be replaced if the damage is major.
Clean the tube extremely well, then under good light, inspect it for nicks that may have cut the seal. Use a razor blade to judge any imperfections you see. If the razor catches on any small pits, they will need to be dressed and have the edges removed before the new seal is put in. Nicks will almost always be at the back of the fork tube. Deep or large scrapes or gouges may not be repaired successfully. To keep the fork light, the outer tubes are very thin, and they can be dented right through fork guards in a crash involving another machine. The inner tube must be replaced if the damage is major.
Small nicks from the front tire hucking rocks at the rear of the tube can be dressed. I use a fine-grit, tapered sanding tip like this one in a Dremel tool. A Scotch-Brite tip or a Cratex tip (grit in a rubber compound) work well, too. Don't get carried away. You just want to knock down the edges. As soon as the razor blade will slide across the nicks without catching, the nicks won't bother the seal.
Small nicks from the front tire hucking rocks at the rear of the tube can be dressed. I use a fine-grit, tapered sanding tip like this one in a Dremel tool. A Scotch-Brite tip or a Cratex tip (grit in a rubber compound) work well, too. Don't get carried away. You just want to knock down the edges. As soon as the razor blade will slide across the nicks without catching, the nicks won't bother the seal.		 Dump the oil from the outer fork leg into a drain pan. Make sure the oil drains completely. Once the outer tube has emptied, push in the cartridge rod and release it. It should spring back to full extension if the cartridge is still pressurized fully. If the cartridge rod doesn't return, the inner cartridge must be serviced, and it will require more special tools.
Dump the oil from the outer fork leg into a drain pan. Make sure the oil drains completely. Once the outer tube has emptied, push in the cartridge rod and release it. It should spring back to full extension if the cartridge is still pressurized fully. If the cartridge rod doesn't return, the inner cartridge must be serviced, and it will require more special tools.		 Since we are only dealing with the outer chamber oil, we can fill it from this end and not bother with removing the top fork cap or the cartridge. The manual will tell you the correct volume. We put in 10cc less than the specified amount since we couldn't be sure that the outer tube was completely drained.
Since we are only dealing with the outer chamber oil, we can fill it from this end and not bother with removing the top fork cap or the cartridge. The manual will tell you the correct volume. We put in 10cc less than the specified amount since we couldn't be sure that the outer tube was completely drained.
To complete the reassembly you will need another special tool, but you can make this one out of a plastic sandwich bag. Cut off the corner of a quart-size bag.
To complete the reassembly you will need another special tool, but you can make this one out of a plastic sandwich bag. Cut off the corner of a quart-size bag.		 Set the bag corner aside and use some light grease on the seal and the wiper.
Set the bag corner aside and use some light grease on the seal and the wiper.		 Put the cut bag over the end of the steel fork tube. Without the bag, the machined edges where the fork bushing sits are very sharp, and they will cut the seal while it goes on.
Put the cut bag over the end of the steel fork tube. Without the bag, the machined edges where the fork bushing sits are very sharp, and they will cut the seal while it goes on.
Slipping the greased seal over the bag keeps the seal safe. Slide the wiper on first, drop on the snap ring, then carefully work the seal over the bag and the sharp edges. After the seal is on, remove the bag corner and slip on the spacer and bushings.
Slipping the greased seal over the bag keeps the seal safe. Slide the wiper on first, drop on the snap ring, then carefully work the seal over the bag and the sharp edges. After the seal is on, remove the bag corner and slip on the spacer and bushings.		 The assembled inner leg should look like this. Set it aside while you prep the outer tube.
The assembled inner leg should look like this. Set it aside while you prep the outer tube.		 With the fork in an appropriate vise or held upright by your helper, ease the fork spring over the cartridge rod. Slide in the damping adjuster tube. The bottom end is indexed in a Showa, but not a Kayaba. The rod will only drop in fully when it is rotated correctly. On the Showa the rod is below the top of the cartridge rod, but on a Kayaba it extends a bit above the top of the rod.
With the fork in an appropriate vise or held upright by your helper, ease the fork spring over the cartridge rod. Slide in the damping adjuster tube. The bottom end is indexed in a Showa, but not a Kayaba. The rod will only drop in fully when it is rotated correctly. On the Showa the rod is below the top of the cartridge rod, but on a Kayaba it extends a bit above the top of the rod.


 

 

Slide the inner fork tube over the fork spring and damping rod.
Slide the inner fork tube over the fork spring and damping rod.		 Slip the seal and wiper up near the axle clamp. The bushing on the end of the steel tube will slide right in. The other bushing will need to be forced in. Let the spacer sit on top of it as shown.
Slip the seal and wiper up near the axle clamp. The bushing on the end of the steel tube will slide right in. The other bushing will need to be forced in. Let the spacer sit on top of it as shown.		 Use a seal driver like this one from ESP (818/249-6744) to drive in the bushing. Seal drivers are available from Race Tech, Motion Pro and the bike manufacturer. It makes this job easy.
Use a seal driver like this one from ESP (818/249-6744) to drive in the bushing. Seal drivers are available from Race Tech, Motion Pro and the bike manufacturer. It makes this job easy.
When it fully seats, the seal driver will generate a solid clack. You will hear the difference in the sound when it is in right.
When it fully seats, the seal driver will generate a solid clack. You will hear the difference in the sound when it is in right.		 After the bushing is seated, slide down the seal and start it in with your fingers. Use the seal driver to knock it all the way in. As with the bushing, when the seal seats it will produce a solid, sharp sound. Plus, when you look in the seal bore, you will see that the snap ring groove is fully exposed, so the snap ring will seat easily. Push in the snap ring with your fingers, then use light pressure from the seal driver to lightly seat the snap ring all the way around. Inspect it visually to make sure it is seated.
After the bushing is seated, slide down the seal and start it in with your fingers. Use the seal driver to knock it all the way in. As with the bushing, when the seal seats it will produce a solid, sharp sound. Plus, when you look in the seal bore, you will see that the snap ring groove is fully exposed, so the snap ring will seat easily. Push in the snap ring with your fingers, then use light pressure from the seal driver to lightly seat the snap ring all the way around. Inspect it visually to make sure it is seated.		 Use your fingers to push in the wiper. The seal driver is not shaped to drive the wiper in without damaging it. It takes a good push but will go in with just finger pressure.
Use your fingers to push in the wiper. The seal driver is not shaped to drive the wiper in without damaging it. It takes a good push but will go in with just finger pressure.
Push down the fork tube and slide the special tool or a 12mm wrench under the lock nut. Thread on the base bolt. There is a rod that extends from the base of the Showa bolt, and it has one flat side. The small rod inside the cartridge rod also has one flat side. Make sure the rod is inserted into the tube correctly before you thread on the base bolt. Use a torque wrench to tighten the base bolt against the lock nut. The manual has the torque specification.
Push down the fork tube and slide the special tool or a 12mm wrench under the lock nut. Thread on the base bolt. There is a rod that extends from the base of the Showa bolt, and it has one flat side. The small rod inside the cartridge rod also has one flat side. Make sure the rod is inserted into the tube correctly before you thread on the base bolt. Use a torque wrench to tighten the base bolt against the lock nut. The manual has the torque specification.		 The base bolt is then torqued into the axle clamp casting. This torque figure is much greater than the torque against the lock nut. Use the axle to hold the fork while you tighten the bolt. All that is left is to put the fork legs back on the bike. Remember how you counted the rebound clicks? Set the rebound back to the number you counted before you ride. Once you do this a couple of times, a fork seal will be a 30-minute job.
The base bolt is then torqued into the axle clamp casting. This torque figure is much greater than the torque against the lock nut. Use the axle to hold the fork while you tighten the bolt. All that is left is to put the fork legs back on the bike. Remember how you counted the rebound clicks? Set the rebound back to the number you counted before you ride. Once you do this a couple of times, a fork seal will be a 30-minute job.


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VIDA LONGA ...  Inserido Wednesday 30 April 2008 23:09

Blogue de aventura : Moto TT, tudo o que precisa saber, VIDA LONGA ...

Tech How-To
Just as you wouldn't go wring out the motor before break-in, you shouldn't ride a new bike without prepping it. If you do, you may not pay the price after the first few rides, but the tab will come due. When the bike is showroom clean the basic prep and setup takes less than half the time it would if the bike were dirty. So bite the bullet and get it done.

While you're handling the basic greasing and checking, spending a few dollars wisely can save you big bucks later in the moto or further down the trail. This bike is one of those leftover '06 bargains available at the moment. Even though it isn't an '08, it's brand-new. Every step we took with this bike applies to any year or brand, but take the time to learn about the brand you choose. Different bikes may need different weaknesses taken care of. This Honda didn't require the bolts holding the plastic to be thread-locked, but some brands might. The idea is to give your bike the prep it needs. Off-road prep would be more dedicated, and it would include flat protection and bike protection items. The key is to take care of any issues before you get the bill for ignoring it.

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Starting with a new, clean machine makes the job of prepping the bike easier and faster. If you plan on adding protective products or making changes, be sure you have the products, chemicals and parts that you need before beginning.

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We decided to dive in head first. We removed all the parts that needed grease before we began putting things back together. The key items were the steering head, linkage and swingarm pivots.

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Steering head bearings look like car wheel bearings but face different problems. You can pack them solid with grease, but the main point is to immunize them from water that will get to them thanks to the prevalence of pressure washers.

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When the linkage and swingarm pivot bearings are all clean and moisture-free, they just need good grease. Slide the inner collar over and grease one side of the bearing, then slide it to the other side and grease it. Easy and clean.

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After lubing the bearings, we installed and torqued the swingarm and linkage. We then removed the chain adjuster bolts and put anti-seize on the threads to avoid having corrosion weld them into the swingarm. Repeat this step often.

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The brake pedal pivot has no bearing and the pedal itself is generally fairly soft aluminum. Grease the pivot and bolt well to prevent the pivot from wearing prematurely.

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The brake pads must be removed to pull the brake calipers from their caliper mounts. Get some grease down inside these holes with the rubber boots sealing them. Make sure to clean up any you slopped on the outside.

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You'll also need grease on these pins. The caliper is supposed to float on these pins to center itself over the disc. If the pins dry out, the caliper won't float, and it will generate a lot more heat than it should have to deal with.

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Make sure the rubber boots are seated when you put the caliper back on the mount. Use a small amount of anti-seize on the threads of the brake pad retaining pins. You don't normally remove the pin that often, and it can corrode to the caliper.

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To remove the swingarm we had to unscrew these hose guides from it. The screws holding the guides are small and don't engage many threads, so we used a thread-locking compound on them.

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This is the perfect time to install SealSavers (www.sealsavers.com) or Shock Sox (www.bermmx.com) to protect the fork seals. The front tire throws rocks at the back of the fork leg and the dings ruin seals. These products triple seal life.

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Most bike-prep services don't include tightening the spokes. This Honda had spoke tension that was fine, but going a little tighter doesn't hurt. Work around the wheel, making adjustments no greater than 1/4 turn at a time. We went around each wheel twice.

 

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The owner of this bike is stepping up from an older CRF450R; knowing he wanted lower gearing, he slipped on a Sunline 49-tooth sprocket to keep the chain and sprocket wear consistent.

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When the wheels go back on, the axles need a light coating of grease. The axles don't turn inside of the wheel, so the grease isn't for lubrication. It's to prevent the axle from rusting to the wheel bearings.

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It doesn't matter whether you use a bike for motocross or off-road. If you're buying your own sprockets, use an O-ring chain. Installing an O-ring chain, like this Sunline unit, while the sprockets are new will greatly extend chain and sprocket life.

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When the fork tubes go back in the clamps, the bolts should get grease or anti-seize on the threads. Then follow the torque specifications in the manual. The Honda specifies 19 Newton meters for the fork and axle clamp bolts.

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This will be an all-around bike, but even if you only ride moto, hand guards are a good idea to minimize roost abuse to your hands. Sunline, Acerbis and Cycra all make guards that are light and mount easily.

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Staying with the same brand and model of bike let this owner save some cash by swapping his triple clamp and oversize handlebar over to the new bike. He installed push-button fork bleeders at the same time.

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An hourmeter is almost indispensable for a new four-stroke. We found that we save money by not changing the oil too often. It takes longer for the hours to add up than you'd think. Recording the stock suspension settings is a great help.

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Since this bike will see some off-road use, it was necessary to make sure it was legal. The owner researched the options and he felt the Pro Moto Billet end-cap would best suit his needs and budget. It installed cleanly and easily.

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Another potential savings is a glide plate (motocross) or a full skid plate (off-road). Current lightweight engine covers are more prone to damage than ever. Put better protection on while the frame tubes are still straight and the cases are whole.

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Radiators are the Achilles' heel of modern bikes, but there are clever innovations in radiator bracing from complete cages to light, one-sided units. We prefer maximum protection that allows use of the stock air-guide louvers.

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Some riders pull off all of the stock plastic and replace it with a complete aftermarket kit like this one from Acerbis (www.acerbis.com). When they sell the bike they put the new stock parts back on.

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For off-road or rocky motocross tracks, an upper fork protector can save big bucks. These Light Speed (www.lightspeedperf.com) units are as light as air. Dicks Racing (www.dicksracing.com) has super-tough ABS units for more extreme protection.

 

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