Yes I suppose that is the correct terminology. There are 8 bolts and when it came apart there were semi-circular half-moon shaped washers, one on each bolt. Each washer was about .5mm thick although I didn't measure them.
When my friend bolted it up he did so without the shims since he lost
about half of them. Then the engine wouldn't start ... by not starting, I mean the starter couldn't turn the engine past the compression
. With them compression
levers off, the starter would barely turn the engine over. We tried three different starters including the one from the other engine that we knew to be working fine. No Joy same issue.
Anyway since we didn't have a ready supply of the half moon shims, my friend made some out of plain stock. I have no idea what the thickness of those washers are but when he installed the washers, the engine now starts and runs fine.
I guess now that we know the shims need to be there and my little online research
turned up a manual that describes how to calculate the shim thickness, my question would be this:
What was binding that would cause enough resistance that the starter couldn't overcome it?
AND related to that, is there some alignment that should be done between the engine mounts and the pinion shaft and or the mating surfaces?
I did notice that when we nudged the engine onto the pinion shaft that the whole drive leg had to be tilted a bit down to fit and that the flanges between the engine and transmission
were not perfectly parallel. My thought was that the engine need to be raised up via the front mounts to get a better alignment and therefore less stress on the pinion shaft and pinion shaft bearing. But that's just the Saturday mechanic
in me thinking out loud.
I cannot find a Yanmar manual that describes the process of mating the engine to the sail-drive and what the tolerances should be.