Johnson 1978 15hp crankshaft play?

[Sailpower]

Hi, I'm working my way through a 15hp Johnson, manual start from 1978 with CDi ignition.

I've converted from L/S to S/S and replaced the impellor, thermostat, put in a fuel pump kit, carb kit, replaced head gasket and cover gaskets with the powerhead off. The compression didn't lift from 75 psi on each cylinder. It occasionally starts and runs for 30 seconds or so, sometimes a little more, so its getting better, but I was advised locally to look at the top crankshaft seal for air leaks.

In looking at this, I noticed there is sideways play on the flywheel, seems like more from port to starboard but a little fore and aft as well. This didn't seem healthy to me, usually indicating a bearing being worn out. I'm going to strip it anyway but any thoughts from the forum? Should there be any movement at all on the flywheel?

 

[F_R]

Re: Johnson 1978 15hp crankshaft play?

Should not move sideways. At least not more than a couple of thousandths. If it is sloppy, expect to find a train wreck when you get inside.

 

[Sailpower]

Re: Johnson 1978 15hp crankshaft play?

Hi F_R - thanks for the reply - I would compare the amount of movement to a wheel bearing, or maybe less, so probably less than 10 thou?
I'll really have to have the flywheel off and do it more accurately - still seems like more side to side than fore and aft.

If some is allowable, it might be OK, just after working on cranks with roller bearings there isn't much at all.