Reply To: 1957 johnson 18hp fuel mixture

[duralark]

Fleetwin, thanks for all the ideas. I’m interested in anything that would allow air to leak into the crankcase enough to prevent fuel/air mixture being drawn from the carb thru the reeds. The carb is not the problem, nor is the ignition (good spark from new coils/points/condensers on both cylinders, nor is compression (65-70 psi on both also).

The damage to the seal at the top of the driveshaft you describe is interesting. It would appear from the parts diagrams that there are no crankshaft seals as such; is this right? Does the seal you mentioned serve as a crank seal? I’m wondering how it could be intended to keep water out of the gearcase, since it’s about a foot above the waterline…? So I guess I’m going to pull the powerhead and see what I see. The shock absorber in the driveshaft is also something I’ve never seen, so this is new territory for me too. Thanks again, and I’ll let you know what I find for sure.

Bob / Duralark

1954 Johnson 5-1/2

1956 Lark 30hp

1958 Lark 35hp