8hp Mercury 2 stroke smokes excessively, has milky oil coming out of exhaust ports

[platothetoad]

I just picked up an early-mid 1990's (I can't figure out how to date these things) 8hp 2 stroke Mercury on Craigslist. The seller said it was winterized 2 yrs ago and not started since. It fired right up on the 2nd or 3rd pull when I got it home, but it smokes like crazy. I figured it might be trying burn through the fogging oil, but after 2-3 minutes it would still smoke heavily when I gave it ~1/2 throttle and I noticed tan milky looking oil running down the back of the leg from the exhaust ports. Is this likely from fogging oil and/or an out of whack carburetor, or something more sinister? The milky looking oil seems bad to me. Thanks for any input.

 

[roscoe]

Fogging oil, exhaust gases, and unburnt oil along with cooling water will make a milky goo.
Also, too many people are putting way too much oil in the fuel mix.

I would suggest running it a while, above 1/4 throttle.
Then examine the plugs, and clean them.
Get some fresh fuel with correct oil mix if you haven't already.
Then run it a bit longer and check out the plugs again.

The plugs will likely have oil and gas on them.
If the plugs have water on them, thats a problem.

 

[platothetoad]

Are these 2 stoke Mercury motors 50:1 or 100:1?

 

[Georgesalmon]

50:1

 

[platothetoad]

That's what I thought. I'll check the plug and try running it with some fresh gas for a while. If it's still smoking real bad I'm sure the carb could use a cleaning. Thanks for the input

 

[Scott Danforth]

best to run it under load and get some heat into the motor. sounds like its been sitting with fogging oil.

BTW, two strokes are supposed to smoke a bit.

 

[platothetoad]

I'm familiar with the smoking habits of 2 stroke, but this was excessive. When I opened up the throttle I nearly lost sight of the motor in the ensuing cloud. It acted as if I was actively fogging the motor, which could give credit to the notion that there has been a lot of fogging oil sitting in the carb/cylinders for too long.

 

[quicktach]

Decarbonizer will give you lots of smoke too......fresh gas mix at 50:1 ...and run engine till smoke clears..clean plugs afterward