Johnson 25hp idle problems

[bartborchardt]

1991 Johnson 25hp Tiller

I'm starting to have problems with the idle. When I give it gas it runs fine. I have noticed a fuel/oil residue coming from the bottom of the couling. There is a lot of residue around the motor as well. I've rebuilt the fuel pump and looked at all the fuel lines and can't find a leak. Could it be that it's just running too lean? If that where the case then where is all the residue coming from? Also, why don't these motors have a breather or is mine just missing? Seams like a lot of debris could get in the carb.

 

[SgtRock]

Re: Johnson 25hp idle problems

There is a small (1/8" ) nipple undr the carbs. a line should run from the bottom carb to that nipple. If the line is off or cracked, it will exhibit your exact symptoms. I have this same motor and had the same problem. (bad idle, fuel/oil in bottom of cover, running down lower unit). The line had come off. Reattaching it fixed the problem. These motors do not have an air filter. In fact none of the 6 OMC motors I have owned had one. The 175 has a plenum/silencer, but the smaller ones just have an open carb.

Hope this helps.