Home › Forum › Ask A Member › 1987 Johnson 9.9 upper crank seal › Re: 1987 Johnson 9.9 upper crank seal
May 4, 2018 at 8:59 pm
#75353
Bill raises a good point, those upper mounts can surely make a mess in many different ways…One other possibility might be that the engine might be breathing the raw fuel vapors leaking out from the upper seal/leaky crankcase halves, causing it to run richer with the cover on….