Snowmobile Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
43 Posts
Discussion Starter #1
Hello all , new to the site and looking for advice. I just picked up my first machine, 1991 Indy 650 , on Saturday, pretty stoked about it but just discovered a clutch issue. I'll try to explain to the best of my abilities and go from there.

When I brake and stop, the motor comes back down to idle and shakes the entire sled (assuming this is the primary clutch disengaging causing the vibration) . I popped the hood and discovered the outer sheave on the primary is wobbling, the center bolt is wobbling too. Good news is that the sheave on other side is straight as an arrow so I'm thinking the the crank is fine (or maybe not :eek:). What should I do here, do I have to pull the clutch and send it in for repair or is this something I can fix with it right on the sled? I'm not going to ride it until that part is fixed, I don't want to be pulling the motor in 100miles cause of a bearing or crank going out. It was rebuilt less that 500 Miles ago, has 150 PSI across the board.

Thanks all
 

·
Super Moderator
Joined
·
17,904 Posts
You will need to pull the clutch to see what the problem is. After the clutch is off, it would be a good idea to do a check of total runout on the PTO stub to make sure it's not the crank. Good luck, it doesn't sound good either way :(
 

·
Registered
Joined
·
43 Posts
Discussion Starter #3
You will need to pull the clutch to see what the problem is. After the clutch is off, it would be a good idea to do a check of total runout on the PTO stub to make sure it's not the crank. Good luck, it doesn't sound good either way :(
I'm thinking bushing, hopefully.
 

·
Registered
Joined
·
43 Posts
Discussion Starter #4
Thoughts? This is a pic of the inside of the clutch.

Crank side has no marks, I gave it a quick sand to get rid of any debris, it's smooth.

 

·
Super Moderator
Joined
·
17,904 Posts
Did you check the PTO stub? You can get an idea if the crank has problems by pulling the plug and having someone pull the recoil as you watch the PTO stub. If it doesn't appear to have any movement, it could be just the clutch. A dial indicator will tell you if the runout is within spec, most shops have one. They may charge you a bit to set it up, but it shouldn't be too much.

The inside of the clutch should be smooth and mate perfectly to the PTO stub. That one has some serious grooves in it!
 

·
Registered
Joined
·
43 Posts
Discussion Starter #6
I did, the crank seemed fine, not bent, still going with the clutch on this one.
The grooves tell the whole story, I love dropping money on something that was supposed to be "good to go". I paid $800 for the machine, what could one expect :p
 

·
Sconnie
Joined
·
1,745 Posts
I would say its just in the clutch too if runout is good... But when you get another clutch, let me know if you want some specs on clutch tuning that i've used! It really wakes up the rxl!
 

·
Registered
Joined
·
43 Posts
Discussion Starter #8
I would say its just in the clutch too if runout is good... But when you get another clutch, let me know if you want some specs on clutch tuning that i've used! It really wakes up the rxl!
Problem is I don't have to tools to take them apart. I know the one that's on it has the red spring if that means anything.
 

·
Super Moderator
Joined
·
17,904 Posts
You can remove the cover with regular mechanic's tools. That gives you access to the spring and weights. Loosen all 6 bolts that hold the cover, remove 4, leaving two opposite of each other. Then work back and forth, loosening the remaining two. As you remove the bolts, the tension of the spring decreases. By the time you have the bolts all the way off, there is very little tension left. The cover may pop a little, just have your hand on it as you turn the bolts the last couple of threads.

When removing weights, remember which side the nut is on. It makes a difference. Use blue loctite on the nuts.

It helps to have another set of hands when putting the cover back on, especially with a new spring, although I have done it without help. On the cover there is an X. On the spider inside the clutch, there is another X. Make sure those X's align to maintain the balance of the clutch.

When looking for a different clutch, make sure the offset of the clutch you are looking at matches the offset of your clutch. Pretty much any clutch off of any triple will work, but some of the twins have a different offset. If you use a clutch with the wrong offset, it will take out your crank seal.
 

·
Registered
Joined
·
43 Posts
Discussion Starter #10
I found a rebuilt clutch off of a 650 RXL, I pick it up tomorrow. Thanks for the clutch 101 insight, they aren't as difficult as I thought, you here "clutch" and you think the worst.
 

·
Registered
Joined
·
43 Posts
Discussion Starter #12
Good news, put the new (used) clutch on , it's a whole new sled, no more vibration and engages at 4000 rpm, huge difference, thanks for your help.
 

·
Sconnie
Joined
·
1,745 Posts
if you ever want to clutch it even better let me know like i offered earlier! with just a different primary spring, weights, and secondary spring that sled goes like crazy!
 

·
Registered
Joined
·
43 Posts
Discussion Starter #15
just make sure everyhtings tight dont ant it to explode on ya when your hammer down on the trail haah
Torqued to spec, I'll check the through bolts for tightness tomorrow morning.
That would be all too scary.
 

·
Registered
Joined
·
43 Posts
Discussion Starter #16
if you ever want to clutch it even better let me know like i offered earlier! with just a different primary spring, weights, and secondary spring that sled goes like crazy!

Here's the thing, it had a built clutch on it, it engaged at 5K RPM and had the spring weights and has the secondary spring on it. I didn't like it, I wanted something I can take my kids on, I just wanna use this sled to run the gear out to the lake and back and the occational tour. It's already been jetted and has triple pipes on it so motor wise it's pretty quick. If I wanna go fast , my soon to be GSXR 750 when I buy it in the spring will get my blood flowing :D
 

·
Registered
Joined
·
43 Posts
Discussion Starter #17
Took it for a 15 minute ride today, vibration is back but not at bad. It's the same belt , ran out of cash as the clutch was 2 bills. No noticeable movement on the clutch still, i'll have to put a dial indicator on it tomorrow.


Goes like stink, it's got so much torque the rear end will slide, crazy power these triples make.
 
1 - 17 of 17 Posts
Top