Replacement 650 Crank shaft collar.

FreeFall7

FreeFall7

Location
West Michigan
I've got a 1994 FX-1.
It has a GroupK 650- 701 big bore kit on it. So it useing a 6m6 case, 6m6 cylinders opened up to 81mm. And a oem Yamaha crank.

I had a air leak on my cylinder base gasket so I pulled the motor to disassemble and inspect the rest of it.
It all looked good except for my rear crank bearing. I ordered a new oem crank bearing and seals. In the process of removing the collar behind the rear bearing that the seals ride on I got couple dings on it. I called my Yamaha dealer to get a replacement and he sed they are discontinued for the 650 6m6 motor. I noticed the part number is the same for this part from 1990 - 2015 except for the first three letters witch are the motor designation.

So I guess I need to know if these collars are all the same ?

Any input / advice woulde be great.
 

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augustaf

augustaf

Location
central florida
Looking at your picture, the ding is in an area where the seals do not ride. (the 2 concentric rings/wear marks on the sleeve) If that is so, reuse the sleeve, I've done that a few times.
When reassembling your engine, I suggest you apply Permatex "High Tack" (available at automotive jobbers) to the base gasket surfaces if using a/m gasket (does not have the printed on sealer like oem gaskets)
 
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Dartman

Dartman

Location
usa
no, the later model collars are not the same
the later style are just a thin sleeve not a thick collar like you have
just buff the nicks and your good to go as it does look like its not a ride area of the seal
 
FreeFall7

FreeFall7

Location
West Michigan
Yeah. I had that thought. I'd rather replace it but since it doesn't look like I have that option I'll have to buf it. Do the new motors use the same seals?
 
Dartman

Dartman

Location
usa
seals are all the same
o.d. size of the collar didnt change
in 98 i think they changed the crank and collar combo
 
FreeFall7

FreeFall7

Location
West Michigan
So. I called SBT today And one of the parts techs went and got one of there collars and measured it for me right than and there!! It Measures the same as mine!! So I'll be ordering one tonight.
 
D

Daddydune

Location
California
So how do you get the old collar off the shaft?
My crank had so much play between the collar and seal I don't know how it ran. I ordered a collar from SBT got it and the seals fit very nicely on it. Tried to pull the old collar off and no success. I tried to grind or cut through the collar and that did not work. I welded a couple of nuts on the collar and put a puller on it and still it did not move any. Tried to heat the collar and then pull it off and still no luck.
It almost looks like there is no collar on my crank, I can't see any lines that would indicate collar/crank.
So how do you get these old collar's off????
Thanks for any help anyone has.
 
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