BELT SLIPPAGE ISSUE AS INDICATED BY YAMAHA
Motorhead Mark Lester
Wednesday, April 11, 2012
Love your show! I'm considering a 2012 Outlander 650 XT. Does the drive belt slip in the clutch and burn up like the Yamaha videos show on the Yamaha website or has this problem been fixed?
If it does, I will probably go with a Grizzly instead.
Thanks for your email!
Here's the deal. All Can-Am and Polaris ATVs and certain models from other OEM's use a CVT system which engages the drive belt to initiate movement as RPM rises.
This is why the CVT tranny used in ATV's (pioneered and in use in snowmobiles as well) uses the term "clutch" for the transmission. Essentially, the Can-Am/Polaris system acts like an automatic clutch at engagement RPM.
Yamaha, Suzuki and certain other models from other OEM's use a CVT system employing a "sprag" or centrifical clutch device (similar to a chain saw drive clutch) mounted on either the crankshaft behind the primary pulley or on the jackshaft behind the secondary pulley.
This system sees the drive belt always "engaged" In other words the drive belt is not asked to be pinched every-time you initiate movement.
The sprag clutch behind the primary or the secondary when spun fast enough engages and initiates movement. The system which sees the sprag located behind the secondary is very good in cold weather as it allows the primary and secondary to spin as soon as the engine starts and helps warm the drive belt.
Now, which system is better - the Can-Am/Polaris set-up or the Yamaha/Suzuki system? If you subject your ATV to repeated engagement events under heavy loads and don't select low range (such as when slogging deep mud or plowing snow or towing a heavy load) you will heat up the drive belt and could "dent" it by literally burning the primary pulley into the drive belt. Not good.
However, if you select low range this situation is highly unlikely to occur. In the case of the sprag clutch system repeated engagement under heavy loads in high range will eventually hurt the sprag clutch, over heating it and generally deteriorating the sprag - but it will likely not create a failure situation until you've done this many times over.
In my opinion a Can-Am is no more susceptible to clutch and belt issues than any other ATV when used properly (low range when loaded heavily).
Keep in mind the system used by Can-Am and Polaris is subject to way, way more load and abuse in snowmobiles which typically have anywhere from 80 to 175 HP going through the CVT with belt engagement. This kind of load is exponentially higher than any current production ATV and it is handled with exceptional reliability.
There you go!