The most important part of the clutch are the friction plates. They take the most wear and tear, not to mention abuse! Friction plates are designed to be an item that is expendable. They are supposed to wear out, as a result they need to be replaced occaisionly. How often, depends on you. If you are racing, we suggest every 3 races. This is due to the need of feathering the clutch to stay up on the power band. If you are doing normal street riding, you can figure once a year. If you are doing abnormal (?) street riding, .i.e., lot's of wheelies, burn outs etc, you can expect to replace the clutch quite frequently.
Friction plate life can be somewhat
lengthened by doing a few simple things. First and foremost,
use a clutch that is of the highest quality. Be sure all related
components are in excellent condition. This means ALL related
stuff. Your clutch springs, hub, pressure plate, outer basket,
push rods, clutch cable, actuator mechanism, and the lever and
perch. The correct amount of oil, and the correct type and viscosity
of the oil is a must! Also keeping the oil fresh is a plus. All
of these items will affect how well the clutch works and the
"feel" of the clutch.
Proper clutch operation requires
all of the clutch components to work well together. The YSR has
one metal plate. It must be in good conditon to operate properly.
Check it for correct thickness, and flatness. It can have no
hot spots or discoloration. If any of these criteria are not
correct, replace it!
Weak or fatigued springs are
a major area of poor clutch action. Weak springs will cause slippage
and premature wear. All four springs must be the same type. Excessively
heavy springs can cause problems also, such as, but not limited
to, premature accuator failure, excessive stress on case covers
|Friction Plate Min/Max Thickness||2.7mm-3.5mm|
|Metal Plate Thickness||2.0mm|
|Metal Plate Warpage Limit||0.05mm|
|Clutch Spring Free Length (Min)||28.2mm|
|Push Rod Bending Limit||0.2mm|
|Pressure Plate Screws Torque||4.3 ft/lbs|
|Clutch Boss Nut Torque||32 ft/lbs|
|Tranny Oil||600cc (No Synthetics)|
The stock from the factory YSR
clutch is a barely adequate unit. The springs are way too weak
and the friction plates are lacking in a big way. We would strongly
suggest replacement with our clutch kit, however, just replacing
the clutch is not enough. PROPER ADJUSTMENT is mandatory!
There are two push rods and
a ball bearing involved in teh clutch acctuatings process. The
push rods tend to get a big dimple in their ends over time. They
are inexpensive, and replacement will enhance clutch action.
Lube it. Adjust it. Life is good!
The Clutch Kit, when properly installed and adjusted, will greatly enhance the delivery of power to the rear wheel. Don't leave home without it!
That's it for this month, shoot
me some E-mail if you
have specific YSR questions and I'll do my best to answer them
as time allows, and/or suggestions for topics in "Tech Tips!"
Remember this page is for you!