HPD'd clutch instruction with its clutch kits suggest using a different washer on the retaining bolt for the drive clutch. Its thinner. HPD said only "It alters when the clutchengages by changing the pre-load." They weren't clear on wether the thinner washer increased or decreased the engagement RPM.

On the one hand you'd think thinner decreased the engagement RPM because it decreased the spring preload. On the other hand, it might increase it because now the sheaves sit farther apart.

Sure would like to know. Any thought guys?

Thanks.

dan

 

help?

 

How much thinner?

 

The original washer is used with the trail profile weights like the stock ones. Whenever you use the race profile weights, which are common in most clutch kits, you use the optional supplied washer. It is actually a snowmobile part number. It keeps the engagement correct on the clutch. The thickness is roughly half of the original and is larger to push the primary outer sheave in a little when you torque it down. Bubba

 

Thanks bubba:

And the continued answer is; it preloads it more and hence will engage sooner. I'm told because the weights are partially opened already. Bit of a surprise that, as the spring tension should have increased too, but...

Dan

 

Dan, the weight design is the key. I can use the optional washer with the stock profile weights and get a good high engagement (race mods of course). It will do the same in any situation when changing the weight profile like that. The actual preload change would be minor, but slightly noticeable. It would all have to do with how the centrifugal weight force acts on the clutches in relation to sheave position. The first explanation is the easiest,though.LOL. I dont really like using the stock trail weights like that with the washer,even on the race setup. When the clutch engages it tends to slam in and can cause a lunge or jump if you give it some throttle. The race profile weights tend to be a smoother engaging weight and I personally feel that has to be easier on clutch parts and belts for sure.I tried a new setup on my wife's wheeler and I really like it. I went with the Polaris brown spring and used the s-55 stock weights. It is easier on the bottom end (not so wheelie happy) and works well. HPD either uses their plain spring with 10AL weights (53 gram) or for the agressive kit the Red/Yellow with 10-58 weights (58 gram). This setup engages earlier than the later and still does the correct top rpms. I am surprised they dont offer that for the trail pipe. I guess it's either one way or the other. It will keep the rpms up better for trail riding. Dan, just keep experimenting with it. Hands on is the best. You'll end up like me and have LOTS AND LOTS of extra springs,helixes, and weights. Bubba