SJ Engine assembly question

[227]

When installing your drive coupler on the crankshaft there is an external O-ring/seal that is suppose to be installed first. So what does that do? I am assuming it is suppose to fit snug around the rear of the crankshaft, however the one I received from Yamaha appears to be oversize and doesn’t look like it fits in there anywhere. I double checked the part number on the package to make sure I got the right one. If it is the wrong one anyway (labeled incorrectly?) When installed on the crank it looks like it will just get smashed away when I tighten the coupler. The parts schematic shows a collar on the back of the crank. I got my crank back with the collar flush, should it have come off set leaving a grove for a proper fitting O-ring to fit into? (I hope that made sense) Anyone familiar with this?

 

[MADMAT]

I don't remember ever seeing that but I could be wrong.

 

[Mile9c1]

I've never seen anything like that. You have the cranshaft assembly. And the coupler threads right onto it. That's it. As long as the crank seal looks like it's functioning properly (i.e. the crank end is the correct diameter).

 

[Shifty]

I think that o-ring is sandwitched between the shoulder of the crank (where the threads end and the smooth portion of the crank contacts the seal) and the coupler. I have seen it on the schematics before. I guess it is there to keep water/ moisture out of the threads of the aluminum coupler. I would think heavy corrosion in there would cause alot of frustration.

 

[SQUARE JOEL!!!]

The parts diagram shows a seal....the necessity of it is questionable.

 

[Freakrider]

use anti-seize on coupler threads....

 

[augustaf]

Use the o ring if your coupler has a recess machined into the flange that contacts the crank collar otherwise don't.

 

[Speedfreak]

I have seen one of those before... Mine laid on the work bench almost all summer before fall garage cleaning