Cracked primary sheaves, how long before?

[Thatspec]

So I just looked closely at my drive clutch sheaves and noticed several small cracks starting way down near the shaft. They are only 1-2mm so far. Wanted to throw that out there to get everyone to take a look at theirs. Its been a big snow week in the NW as many of you know, causing me yet another blown belt. Started a thread here;

http://www.ty4stroke.com/viewtopic.php?t=27162

but thought I better put it here as well. Someone else linked to this thread;

http://www.ty4stroke.com/viewtopic.php?t=26516

which really ought to be looked at as well.

It just doesn't seem like I'm doing anything out of the ordinary to my sled yet my clutches get pretty hot (everything is spot on mechanically). Are you guys all using the stock primary, and how is it holding up?

thanks, Mark

 

[Thatspec]

Talking to Tom Hartman today, he explained that some of these that I think are cracks are likely there from the factory. If you can't catch it with a fingernail, and is less than 3/8" long just keep an eye on it (it will be part of my daily inspection now.

This pic (if I have attached it correctly) is of the one I'm worried about, its about 2mm and can catch a fingernail. Another problem I found is that I still have 16mm rollers, apparently stock on the MT. Supposedly 14.5mm would be the way to go for more belt clamping power (another $60).

The question is do I dump another $300 into this clutch for new sheeves, and rollers, or spend the approx $430 for a brand new P-85. Anyone here using a P-85?

 

[monker]

that is typical for yammi primaries.

 

[rxrider]

Try running a sharp edge over the "cracks", if it hooks up you have found a crack. Keep an eye on them as they grow over time. None of my sleds have cracks like in your picture. If that showed up on my turbo I would be scared. Are both sheaves looking the same? you would benefit from going to 14.5 mm rollers increase belt squeeze at engagement and to decrease belt slippage.

monker - what is typical for yami primaries? that they looks like that and are OK, or that they crack all the time are not OK?

 

[tundra]

i have the same thing, same thing in the hub of the secondary

:ORC

I will buy new one this summer

 

[talldude1]

keep a close eye on them. If you are turboed I would replace it. I had one explode and a chunk the size of a baseball flew off the clutch and messed a lot of stuff up. Did the polaris primary and it is actually a nice setup and worked well. (this was on MM700)

 

[pro116]

I have had 3 sleds that did that and know lot's of them that also have cracks there.

 

[alaskanbowtie]

DAMN...not good!

Talking to Tom Hartman today, he explained that some of these that I think are cracks are likely there from the factory. If you can't catch it with a fingernail, and is less than 3/8" long just keep an eye on it (it will be part of my daily inspection now.

This pic (if I have attached it correctly) is of the one I'm worried about, its about 2mm and can catch a fingernail. Another problem I found is that I still have 16mm rollers, apparently stock on the MT. Supposedly 14.5mm would be the way to go for more belt clamping power (another $60).

The question is do I dump another $300 into this clutch for new sheeves, and rollers, or spend the approx $430 for a brand new P-85. Anyone here using a P-85?

>>
Are the 16MM rollers only on the RX/RS sleds or also on the Apex mnt. clutch ? Have many guys went to the 14mm rollers on the Apex sleds?? I know this isn't Apex forum but wondering if they have similarities? I would be reluctant to run that clutch!