Johnson 200hp,1992, Oily Carb

[winfieldh]

Hi,

The above motor has run like a top for many years. It last ran approx 3months ago with no problems. I just hooked it up to the hose for a pre-departure check and noticed oil streaming down the lower leg. Removed cover and saw oil coming from seal at carb cover. I removed the carb cover and drained about 1/2 cup of oil on top of what already escaped. Once cleaned up and without carb cover on, engine cranked and ran fine. It looks like the lower most carb was the oiliest, but I haven't a clue what to do to remedy problem or what the problem is. I have not replaced the carb cover yet because that is obviously the culprit or somehow rrelated. I have posted pictures of the front of the engine here.

http://picasaweb.google.com/winfieldh/Johnson200?feat=directlink

Thanks for any suggestions.
Winfield

 

[DJ]

Re: Johnson 200hp,1992, Oily Carb

There is a drain tube that runs from the bottom of the air box to the engine intake manifold. What that hooked up?

That tube is to drain any "spit bacK" from the carbs back into the engine.

 

[winfieldh]

Re: Johnson 200hp,1992, Oily Carb

Hi,
If what you are referring to is the tube that runs between the carbs to the bottom of the airbox, yes that is hooked up. There didn't seem to be any oil "sprayed" about the airbox cover. There really isn't any oil above the lowest carb in the airbox cover.

It would seem the airbox cover and the way it is sitting might be the problem, but it shouldn't have shifted from last use to now.

There is slight bit of corrosion on small gold screw on lowest carb, see picture in link in previous post. Don't know if that has anything to do with it. Those gold screws seem to have holes it the center of them. If those are plugged, what effect would that have?

Thanks for the response.
Winfiedl

 

[jonesg]

Re: Johnson 200hp,1992, Oily Carb

Fuel comes out the throats when the engine is tilted, after 3 months the gas evaporates and you are left with oil.
Clean the green corrosion off, might consider rebuilding the carbs if its been a few yrs since.
iBoats sells the carb kits. Simple DIY project.

At the very least make certain every cyl is firing by feeling the cyl heads or use an infra red themometer.

 

[winfieldh]

Re: Johnson 200hp,1992, Oily Carb

Thanks. I was thinking it might be stuck float in carb. They have not been touched in the 5 years we have owned the boat...never had a problem 'til now. The curious part is once the air box is removed it ran fine.

I have cleaned it up, replaced the airbox loosely and will check again in the morning before going to the lake. I am leaving the motor down tonight.

Thanks, W