120 Johnson with oil coming out of exhaust

[90johnson120]

Hi folks. New to the forum. I'm hoping for some insight. I have a 1990 120 Johnson with the VRO disconnected and running with 50:1 mix gas. The motor starts right up and runs with power but smokes excessively at idle. It was this way when I bought it. I have black oil/ carbonization dripping down the cowel from the exhaust, creating a slick in the water. I brought it to a mechanic and he did a compression test - passed with flying colors. Asked me if I was putting too much oil in the mix because he had to adjust the carbs - floats were loose. He also replaced the plugs. I bought a new external gas tank, started with fresh gas - same problem. If I put my hand in the exhaust it gets sprayed with fine oil droplets. Could this be a head gasket gone bad or is the problem in the carbs. Thanks

 

[JB]

Re: 120 Johnson with oil coming out of exhaust

Ahoy, 90Johnny120.

Welcome to iboats. :welcome:

What you describe sounds to me like normal behavior. If your head gasket were failing you wouldn't have gotten good compression readings.

 

[90johnson120]

Re: 120 Johnson with oil coming out of exhaust

This is a tremendous amount of oil. I'm creating quite a slick. I pulled the boat out and created a black puddle on the ramp. Inside the engine cowling there is some black soot but I dont see any leaks.

 

[JB]

Re: 120 Johnson with oil coming out of exhaust

Hmmmmm. Do a compression test. You may be having some misfire and pumping the unburned fuel out the exhaust.

 

[90johnson120]

Re: 120 Johnson with oil coming out of exhaust

Will do. Thanks .