Re: Engine rebuild, help!

Posted by Fish'n Jim On 2022/12/7 11:05:14

Have to check that all the machining was done right. ie, if they missed one or didn't cut it the right size, misaligned, etc. then the oversize bearings will "over"-tighten. The blocks are best align honed, so since that wasn't done it complicates trueness.
eg;I bought a "rebuilt" spare motor for the Cad and the crank journals were all over the map, so it happens. There's certain re-assembly checks that you have to make to guarantee it's going back correctly. A little more art than changing an oil filter.
There's a magic clearance on the bearings to get correct oil flow. So if too tight going back, you'll ruin it.
Just one of the magnified issues with straighties, longer bending moment. Becoming a lost art.
Lots of lost art in those passe rope seals too. Common early issue across the brands.