MX-Z 670 Clutch - Snowmobile Forum: Your #1 Snowmobile Forum

lmassy · 01-15-2013, 03:43 PM

I have a 1999 MX-Z 670.
Does anyone know if it is OK that the outer clutch plate can be turned manually, but the engine doesn't?

I am afraid that the clutch is going to fail when I am out riding or something.

The reason I noticed this is because my recoil broke a few weekends ago and I tried the manual starting procedure of winding the rope around the clutch.
But the engine was not turned over when I did it.
The outer clutch part turned, but the engine did not rotate.

If you can see the picture I attached, I can turn the piece with the arrow on it, but the black HUB with the square on it stays still (so does the motor)

I asked this in my other post, but I think this topic got buried. So please excuse if it seems duplicate.

**smallengineguy** · 01-16-2013, 06:09 AM

No it should not turn. The clutch shaft and outer part are both splined. The splines probably wore out. Remove the bolt and you'll see what I mean.

lmassy · 01-16-2013, 08:36 PM

The clutch works fine once I start the engine.

But it sounds like I am headed for a failure at some point.

Anyone have a clutch for sale?

I think the one on my sled is a racing clutch or something. But I would take any replacement clutch at this point.

minisrint521 · 01-16-2013, 10:51 PM

Your H.O. 670 has different ramps and spring then a reg 670..you can swap them over.

lmassy · 01-17-2013, 07:54 AM

Has anyone out there had this same experience where the outter part can be turned without turning over the engine?

If this is just normal wear & tear, I will leave it, even if I lose a little performance. Or maybe there is a repair kit for this issue?
But if the clutch is a time bomb, then I will spend the money to get a replacement.

**smallengineguy** · 01-17-2013, 05:26 PM

Did you remove the bolt and take the outer off the inner yet? You're gonna see where the splines are stripped out of it.

scrammy650 · 01-18-2013, 04:05 AM

it is time for a different clutch

never seen one do that myself but probly good thing u noticed it now, i had a few yrs ago my clutch bolt wasnt even on there and drove the heck out of it for a few weeks b4 i even noticed it was missing.

lmassy · 01-24-2013, 08:20 PM

I think I figured it out.
The actual clutch is not stripped.
But the rubber HUB is not really attacehd to the clutch via the metal backing plate.

I removed the bolt and the rubber HUB with the splines and could see that the rubber HUB should have been bolted to the outter clutch part.

So it still works fine.
Just not sure if they sell a replacement rubber HUB part?
Or do I even need to replace it?

IRONDOG · 01-24-2013, 08:54 PM

The rubber is supposed to be permanently attached to the "governor cup". You need a new governor cup, Skidoo part number 417004700. You may have catastrophic clutch failure as well as crankshaft damage if you continue to run it like this. Get it fixed.

**smallengineguy** · 01-25-2013, 03:41 AM

IRONDOG is the man. Obey him.

lmassy · 01-25-2013, 07:10 AM

I will listen to IRONDOG.
Do you think this one will fit perfectly?
Ski Doo MXZ Grand Touring Formula Clutch Governor Cup 420480395 417222081 | eBay

IRONDOG · 01-25-2013, 07:54 AM

No, that one won't work. You need one with the rubber bonded to it. The 670 requires a rubber damper to counter certain crankshaft harmonics. Take the part number I gave you to a Skidoo dealer, have him do an interchange in his computer, he will then be able to tell you which machines use the same governor cup.