1975 25hp Johnson problems.

[EMW73]

Hi all,

I just bought a new to me Johnson model # 25el75b. The motor starts and runs ok in a garbage can full of water,however there was what seem to be oil leaking from the spark plugs. I took the spark plugs out and they were black not white so I'm guess thats good. But what would be wrong with oil leaking from the spark plug holes? Also what other steps should I take to ensure all is in working order? The motor runs a little rough,the guy said it had been sitting a little while. I should probably rebuild the carbs. but have never rebuilt a carburetor. Is this something a noob should try? When the motor is running,if you close the throttle the engine dies. Is this normal. Also the motor will not stay at a idle. Is this normal? I'm not trying to spend a bunch of money on this but any help and info is greatly appreciated.

 

[OptsyEagle]

Oil leaking from the spark plug holes sounds like you are not getting a good seal. If that I the case you will not be getting as good of compression as you should either causing many problems. You may need to helicoil those holes or something, depending on what damaged them. Probably someone cranking in a spark plug when the motor was hot and stripping them.

All my motors die when I turn the throttle down to the slowest position so I will say that is normal. Many motors will have an idle adjust to stop that but I don't see why one would bother with it.

I would fix that spark plug hole issue before determining if you have an idle problem or not. Those holes need to be sealed.

 

[EMW73]

Thx,I ordered an original manual off ebay. I was thinking about ordering a carb. Rebuild kit,water pump repair kit,points condensers,and new plugs. Any objections?