Oil on lower drive casing.

[ndusoo2]

Concerning a 15 hp Johnson 1994. <br /><br />I use this engine for a kicker and consequently run it at very low rpms while trolling. I noticed that I have a rather heavy oil sludge build-up on my lower case from the lower engine to about 18" down the the case. Could this be build-up from low rpms or do I have an impending disaster?<br /><br />The oil seems thicker than two stroke oil. More like a sludge.<br /><br />Thanks

 

[Fouled Plug]

Re: Oil on lower drive casing.

Is the "sludge" coming from the exhaust port of the motor?

 

[12Footer]

Re: Oil on lower drive casing.

Excessive idling can cause this build-up. You should blow out the carbon every once in a while. I know you've heard 18 year olds say this about grandma's Towne Car, but it's really the same thing....Only more pronounced when we burn fuel/oil mixtures.<br />These engines are designed to operate at higher RPMs (not exactly wide-open all the time,but higher). Theree are several products you can use to help with this build up. Some are additives, and some are aerosol treatments . Ask your local marina dude which products he would reccommend.(I like the aerosol,as I don't like to put things in my tank what aint gas or oil)...You will also need to replace the impeller more often than normal, as the impeller will be in contact with the pump body walls more than normal.