Yamaha 40elk crankshaft bearing

[Nosinky]

I am repairing an 1985 yamaha 40elk that is on a 1985 starcraft hl150.the top cylinder piston was very scored and the block is getting bored oversize and new pistons and rings will be installed.my question is, the flywheel end crankshaft bearing has two composite type rings on the outer race,where it would contact the crankcase.what is the reason for these?vacuum sealing?,prevent the bearing from rotating?.electrolysis?.the bearing is a simple deep groove ball bearing in its size that is widely used in other applications without the two stripes.i have a replacement w/o the rings,and am considering using it with a thin layer of yamabond on the circumference.im 30+plus years mechanic,but not on outboards,im stumped

 

[99yam40]

If you do not want to get the correct bearing, then you can try what you are saying.
I never like to try stuff that may make me redo a job if it does not work out

 

[Nosinky]

Thank you

 

[Nosinky]

Whats up with the stripes?

 

[Nosinky]

 

[TownsendsFJR1300]

Being a two stroke, the lower unit has to be sealed or it'll leak and run lean.

I suspect if there's not a separate seal to seal the crankcase, those "stripes" either seal the crankcase (if they stick out some), or if their recessed, probably takes some sealer...

Does that bearing seal on the outside or is there a separate seal on each end of the crank? There should also be some sealing between each cylinder as well on the bottom end..


Looks like there's some smaller seals and spacers at each end: https://www.boats.net/catalog/yamaha/outboard-by-year/1985/40elk/crank-piston

 

[Nosinky]

there is a lip seal on that end

 

[Nosinky]

i have the factory yamaha bearing on order by part number.will use it instead.still like to know the reason for the composite stripes.

 

[Faztbullet]

Yammy also uses these in their skis..I myself always thought they where a seal and spacer to keep race from hammering block...

 

[Nosinky]

We'll go with that faztbullet:thumb:
,the extra $20 for piece of mind is worth it