70 Johnson 6HP diagnosis

sffar

Cadet
Joined
Aug 22, 2008
Messages
25
I'm trying my first fix-up of an older motor. This one, besides a split gear housing, has about 60# compression in both cylinders and oil all over the power head that looks like it's coming from under the flywheel. Oil seal? The cylinders are not locked up and seem to move properly when I pull the starter.
Any insight would be appreciated. If the problem is the seal, would that account for low compression? Should I beware of further internal damage? :confused:
I'm still in the process of getting a strap wrench so the flywheel, etc can be removed.
Thanks,
Sam
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: 70 Johnson 6HP diagnosis

60# and even is probably not a problem in a pull-start engine.

A bad crank seal will not affect compression.

Good luck. :)
 

sffar

Cadet
Joined
Aug 22, 2008
Messages
25
Re: 70 Johnson 6HP diagnosis

Thanks, JB. Good to know. So the seal would account for the oil, but there's not necessarily any damage internally as a result. I'm close to getting the flywheel off, so I guess I'll find out more in short order. Maybe I'll get away with seals?maybe rings?and be good. I hope so! I got a gearcase (w/gears) off eBay for $37 (shipped) that's in need of TLC but looks OK. That'll take care of the apparent freeze damage.
 
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