Regular maintenance is needed on centrifugal clutches, but often neglected. The No. 1 thing you can do to extend the service life of your clutches is keep them clean.
During wet weather months, it is not so bad, but in the hot, dry summer when the dust gets deep, I highly suggest periodically removing the clutch cover and blowing the clutches out with compressed air. You may need to blow them out after each ride if the dust is bad enough.
When dust and dirt gets sucked into your clutch intake, it circulates in the clutch area, penetrating the bushings, bearings and sliding surfaces and causing them to stick and bind, which results in excessive heat, premature clutch wear and eventual clutch component and/or belt failure. There are kits on the market to filter the clutch intake air and keep more of the dirt out. SLP offers several but each chassis/engine is a bit different. However, they essentially are performing similar tasks—keeping the clutches clean.
Periodically inspect the condition of your weight bushings and rollers. If running hard in dirty or hot conditions with a heavy load (for example sand or mud), this inspection should be done at least every 500 miles. The weight bushings are replaceable on some models (most aftermarket weights have replaceable bushings as do some OEM weights).
When they get too much play in them, the tips of the weights will move over on the roller and this side-loading of the roller will cause the roller bushing to fail prematurely. If the roller bushings are worn, the entire roller and pin that it rides on must be replaced. If one roller/pin assembly is worn and needs replacing, we recommend replacing all three as the other two will most likely fail soon. These bushings are meant to be run dry, so never apply lubricant to them. If you let the bushings go too long, they can wear to the point that the weight as well as the spider assembly becomes damaged, requiring full clutch replacement.
Clutch Rollers
Driven clutch rollers or square slide blocks should be inspected each time the clutch cover is removed. How dirty the conditions are that you ran in will dictate this as you will be blowing the clutches out on a regular basis. For rollers, if flat spots are detected, replace them as a pair. Keep a close eye on these and replace as soon as you see a flat spot starting because when they flat spot, essentially the roller is skidding on the tower of the clutch. If this skidding action goes on for too long, the aluminum tower will wear and if worn too much, it will require the clutch to be replaced.
For driven clutches with square slide blocks, inspect the slide block and aluminum tower that the slide block rides on for wear. If wear is detected, the slide block can be removed and rotated 90 degrees one time to extend the life of the slide block. If you are looking for a longer service life option, SLP has heavy-duty rollers to replace either the slide blocks or the stock outer rollers. The rollers that replace the slide blocks are larger in diameter than the ones that replace the outer rollers. These rollers are not very susceptible to flat spotting and we see about four times longer service life out of them. An added benefit to replacing the square slide blocks with SLP heavy-duty rollers is the clutches tend to be more responsive as friction is reduced. Failure to replace a flat spotted roller will eventually result in clutch damage that will require full clutch replacement.
Also inspect your belt each time you blow out your clutches. Look for obvious heat signs such as center delamination and inner belt micro cracking. If detected, replace your belt. Also, if you see a cord hanging from the side of the belt, it is time to change it. It is better to replace it now than when you are on the trail in a bad situation.
Another common belt problem is a “burnt” spot on the belt. This is caused by running in high range at low speeds with a high load, like crawling through a section of rocks. The clutch essentially slips on the belt. You would typically smell a burned belt when this happens and may even see blue smoke exit the clutch cover outlet. A quick inspection of the belt would show this burned spot. If the belt has a burned spot, it must be replaced.
