72 Johnson 50hp wont crank with both plugs installed

[citipete]

I have a 1972 Johnson 50hp that seems to have a starter problem. With both plugs installed it will crank to slow to start. When I pull one plug out it will crank and I can nurse it to start on one cylinder. Is this a bad starter or does this engine have a compression release system of some type that is not working. Sure could use some help with this. I have the repair manual on order but can't stand not doing something.<br />Thanks<br />Pete

 

[12Footer]

Re: 72 Johnson 50hp wont crank with both plugs installed

Citipete, Welcome to iboats. No your compression is great (sounds like).<br />The symptoms do sugjest a defective starter, battery, or bad connection to and from it.<br />Try jumping the solenoid with a car jumper cable (the two largest lugs on thew solenoid). Be very careful not to touch the motor frame, and try to shield the carb area, because it may throw some heavy sparks.<br /><br />If it starts easier, the solenoid contacts are fried internally, and you only need to replace the solenoid. No change, or an abundance of sparks (like an arc welder), and you have a short in the starter itself (replace or rebuild).<br /> But first, check the cheap stuff, such as battery, cable connections ect.

 

[citipete]

Re: 72 Johnson 50hp wont crank with both plugs installed

Thanks 12Footer, it is the solenoid.<br />Thanks for your help. Hope you stay around, I've just begun. Ha Ha<br />Pete