Cut the Primary Or Speed Sheave

[sdracer]

Would like to know what your thoughts are on cutting the primary clutch or just buying a speed sheave. Is it worth the time or money???

 

[impalapower]

I'm not into clutching much. What does cutting the primary mean?

 

[AIRWOLF]

I have cut the primary before with good results.

 

[LazyBastard]

How far can you cut the primary without worry about the weights slipping past the rollers?

 

[AIRWOLF]

not sure how far you can go,,,

I took .025 off each sheave

 

[LazyBastard]

So that brings the belt how close to the top?

 

[black john]

cutting

you can not cut very mutch off the in side of the primary as it will crack from the center to the outside and can cause an explosion if it is not found.please be careful this is not sound pratice.

 

[BETHEVIPER]

i have done a few, as for the cracking that has little to do with cuting faces. ive gone to .030 on each side, wont push it to the top but will be close. for any of these mods to do anything you will need to make sure the secondary is shifting out all the way as well. center to center needs to be correct. also on clutches with clickers make sure if you cut them that the weight doesnt contact the sheith when shifted all the way out. make sure there is a little clearence so when the belt blows the weights wont hit the clutch and damage the clutch. 14.5 rollers make this clearance tight or nonexistant.

 

[jtssrx]

stay as far away from the speed sheeve as you can!!!!!!!!!

 

[wolfie]

Re: cutting

you can not cut very mutch off the in side of the primary as it will crack from the center to the outside and can cause an explosion if it is not found.please be careful this is not sound pratice.

I'd leave the job to an expert, who's done it before. But the fact is, many Yammy tuners have done this for years and it is a sound practice, as long as you stay within reasonable parameters. I've heard .010 is perfectly safe. .030 is asking for trouble. It does lower the gear ratio at full shift out and will give you more top end.

 

[sdracer]

jtssrx, Why do you say, stay as far away from the speed sheave as you can?

 

[170plus]

i had my sled working very well,operating rpm,top speed,ect.....wanted more like we all do.....shaved secondary clutch first the proceeded to a speed sheave which i got very cheap so i said why not....drove 60 miles on my sled to my dealer..rogers sport center in ft kent .. with my 2 buddies 1 had xc800 and the other a stock rx1.....didnt change anything else except installed speed sheave ...left the dealer and went for about 80 mile ride home ....wow what a disappointment...lost 800 rpm everywhere , my 2 buddies would run away from me where i was kicking their butt that morning....it took a lot of trial and error to get the speed sheave to work the way i wanted it too but now im happy with the results,put 4000 miles on last years belt with no problems....all i can say is if your gonna try one make sure you dont get you bottle of whoop-a$$ and your bottle of patience mixed up........ i was able to gear down and clutch down for low end and the speed sheave makes up the top end...hope this helps

 

[jtssrx]

jtssrx, Why do you say, stay as far away from the speed sheave as you can?

The speed sheeve is a belt eater. The new sheeve is a different angle. Bad idea your only changing one sheeve so the angles don't match. Plus when you do this on a 2 stroke your suppose to move your motor back you can't do that with a RX-1 the mounts are solid.

 

[muskrat]

JTSSRX is 100 percent correct. I put speed sheave on last year and it did not pull as well, lots of heat and belt slippage, and I toasted a belt in less than 300 miles. It did hold top end speed with a gear down but throwing belts at 100 mph isn't fun. If anyone wants a speed sheave I have one for sale, cheap!

MM

 

[grader]

i agree with jtssrx on the different angles and heat issue but not on the motor mounts. these engines can move alot. my 03 rx had 4000mi. at the start of last year and center to center was perfect the first year. after doing air box mods and a new track,it ran like a raped ape, that is, untill the engine moved. this left me with a top rpm of 9700. it took a while to figure out cause i was also led to believe it was solidly mounted. this also happened to my buddy black john but not as bad on his. we have now installed tensioners to keep things in line. the people that were having top speed issues last year should check this. supertuner wrote an excellent article on clutch allignment last feb. maybe someone on here can post the link.