Need advise
 

Ok today I started my 1988 150 mercury out board and she started right up was idling to high so I turned the idle screw to lower it, she ran great but then the idle lowered by itself and the exhaust started to smoke like as if I was spraying oil in the carbs to winterized it, which I wasn't Almost stalled out but she didn't, the idle started to get higher and the smoke was back to normal, what would cause her to do that? Should I be concerned and also this is the first year that I did not winterized her Thanks as sone as I can figure out how to put pics on here I will Thanks again

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same question same answers

That's not the same question

What's the difference?

you didn't winterize and now it isn't running right....

gummed up carbs... you shouldn't have to adjust anything

what would cause it to smoke extra.... a build up of oil from gas that evaporated..... high idle... running lean....

It pretty much is. You origanally asked about a high idle, and we reccomended you not change the idle as it would probably create other issues and you needed to fix what was causing the fast idle. By lowering the idle you created problems. Most likely you retarded the timing to lower the idle, which is going to cause a poor burn, and fouling of the plugs. 1st you need to put the engine in the water or a tank so as to have water at the height it would be with it in the water(2 strokes MUST have CORRECT backpressure BEFORE you make ANY adjustments to the idle speed as backpressure controls how the engine runs), then you can adjust idle speed if needed. You could just have old gas in the carb bowls that isn't burning correctly, and need to put fresh gas in it, but you never make idle speed adjustment to a carbed 2 stroke unless it is under the same conditions it will be run under.

Thanks ferm I know you are right about that I have to get a drum and put my motor in it to adjust the idle I will be doing that as soon as I get the drum,that's where my son comes in,getting the drum , I never had that problem before where I almost stalled and started to smoke heavy all of a sudden, never seen that before, also the adjustment was very minimal so if I had to I could get it back to where it was before I turned the screw

Most 2 strokes adjust the idle speed via the timing. It only takes 1 or 2 degrees of timing change to REALLY screw up how the engine runs. Fuel needs compression to ignite, and if it ignites even a degree or 2 to late, it may not be under enough compression to fully combust which causes ALL kinds of problems.