In preparation for the top-speed primary clutch mod (where you get a machinist to remove material between the primary clutch sheaves and also at the spider or cover plate to allow the sheaves to move closer together at top-speed), I have removed the primary clutch and separated the fixed sheave from the moveable sheave and spider.

After close inspection, it appears to me that the (un-modified) sheaves can not close all the way right now b/c the spider is making contact with the coverplate too soon instead of the spider making contact with the coverplate at the exact same time that the sheaves make contact. I measured it and I found that if I installed washers on the coverplate that are 45 thousands wide, I could make the sheaves touch at the same time as the spider & coverplate.

My original goal for this project was to make the sheaves close about 80 thousandths closer, but its complicated now that I know my spider/coverplate is touching much sooner than the sheaves touch.

My question is how much should I remove from the sheaves and spider/coverplate to achieve my 80 thousandths goal for the sheaves(keep in mind that my current (stock) set-up allows the spider/coverplate to touch about 45 thousands sooner than the sheaves touch)?

NOTE: I don't think I can remove 80 thousands from the spider contact patches b/c they don't appear to be that thick to me.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

Man Mikey the only one I know that has done that is Kiss....It seems he took .060 off but I will not swear to that.
I would say he is the man to ask. BTW,,,when you removed the primary did you seperate the inner part??....or did you even remove it from the engine??.....if so what puller do you have??
Thanks
02 650 camo

 

Kodiac,
Yes, I know KOD did this mod recently and another guy too (who's name escapes me right now). Good suggestion, I should go ask KOD about this.

***Ok, I think I have figured it out now.***
When I measured my (late model) 03 P650 primary clutch sheaves at WOT position (fully closed), I had approx. 0.040 of space between the sheaves when the spider makes contact with the cover plate (everything is stock). That being the case, I now plan to modify the sheaves and cover plate as follows:

Shave .080 off the cover plate (also add .080 washers) and then shave .040 off the moveable sheave only. As far as I can tell, this should make it close the sheaves approx. .080 more than it does now and also make it where the sheaves touch at approx. the same time that the spider and cover plate touches. Someone please let me know if my calculations are off.


PS - Yes, I separated the fixed sheave from the moveable sheave after I pulled out the entire primary clutch. I used the special puller made for this clutch pulley...I bought a used one from someone on another atv forum. EPI and Dalton both make this puller and they are both reasonable in price. You can also buy the special Kaw. tool to separate the fixed and moveable sheaves (the moveable sheave unscrews from the fixed sheave) or you can do it the cheap way like I did...basically, I clamped the flat edges of the spider in a vice grip and then turned the fixed sheave clockwise (it has left hand threads). To turn the fixed sheave, I inserted a bolt thru the 2 holes at the end of the shaft and then gripped this shaft and bolt with a pipe wrench and turned it clockwise (the shaft is attached to the fixed sheave. Its actually a lot easier than it sounds.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

I was wondering if that could be done without the holder.They make a tool that the fixed part sits in and you unscrew the spider.Now are you going to be able to torque it properly that way?...it seems like the torque is like 180 ft pounds or something like that.Another guy said he bought the puller (EPI) I think and then took the assy to his dealer and they seperated it.He did this for the same reason I want to and that is to replace the bushings.
02 650 camo

 

Kodiac1,
Good question about how I'm going to torque it down when i reassemble it...I thought about that very same question today right AFTER I got the thing apart! Doh...[img]i/expressions/face-icon-small-smile.gif[/img] Actually, my torque wrench doesn't even go to 180 lbs...so I guess I'll just tighten the darn thing as hard as I can with my old worn out muscles and hope it never comes unscrewed while riding down the road. I'm just too darn cheap to buy a special holding tool for this one-time mod, and I also don't want to pay my local dealership to do it for me (they'd probably charge me as much as the cost of the holder tool!).

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

I'm the other guy. You have the newer style clutch; the cover is the limiting factor. Mill the cover in the 4 spots that the spider contacts to allow the sheaves to bottom out, you will gain 40-50 thousands. If you want to go further, turn the sheaves on a lathe and mill the cover a little more, rather than using washers on the cover. Washers will place the cover out further than spec and may screw up the engine braking system. I know one guy that went to 80 thou w/o any problems.

 

I had mine done. Cut 30 tho. off each shieve and cut the pads ,I think 20. Got instructions from Fundy power sports. Great guy to deal with, for any performance parts or his engine mods.

 

NovaKaw and Travelor,
thanx for the feedback.

NovaKaw,
Sorry I couldn't remember your screenname in my post above. I like your idea of just cutting the contact patch areas on the cover instead of the entire coverplate surface (to avoid using washers), but I don't know how to do that. Please tell me how I can get the cover plate machined at just the contact patches? Do you know what type of machine or tool can do this (and still accurately measure how much is removed)? I know a lathe will cut the entire surface of the coverplate, but I don't think a lathe can accurately remove material from certain spots on the coverplate (but I'm no machinist, so please tell me if I'm wrong about the lathe).

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

You will need to find a shop with a mill. It would be an extremely simple job for them. They will need to clearance out slightly further than the actual contact patches to clear some portions of the spider because the four "towers" on the spider radius outward where the flyweights fasten on. Just take the spider and the cover to the machine shop; they will open the cover up enough to give the clearance you will need.

 

NovaKaw,
Thanx for the info...I'll do that!

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]