Yamaha Rebuilding my race engine

[AZCourt]

Split the cases and found the cam chain a lttle stiff. There were a couple broken parts in there too. A bearing retainer for the secondary clutch input shaft was broken and laying in the bottom, as well as the primary clutch bearing retainer ring. One of the secondary clutch shaft bearings is really discolored too, ordered a blind bearing puller to change them out. So for now I have a new crank installed with a corrillo rod, and the grizz gear setup in. As soon as I get the bearings replaced I'll bolt the halves back together. Hopefully have it all done this weekend.

 

[07fj]

this is your 693 Court?

 

[AZCourt]

Its my old 686, gonna be a 693. This engine had been sitting under the workbench for some time. I had another I was racing and rebuilding as the 693, but the counterbalancer is stuck and I ruined the cases trying to get it off. So back to this set of cases.

I dont know if this just happens to the chains, or if it has somethingto do with running this engine at 280 for a couple hours during a couple races.

 

[07fj]

I am thinking the latter! lol, mine is still pretty nice actually since it is original. I ran a few races at 235-240 for many laps.

love that Amsoil