Lean pop and Running Rich

[zarillus]

I have an 89 Evinrude 110 that has a lean sneeze at idle however when i pulled the spark plug in the #1 cylinder its dry,black, and sooty? All other appear normal with just a slight amount of oil on them.I thought that would indicate i was running rich however the damn thing is sneezing at idle.

 

[BonairII]

Any chance that air is getting into the fuel line? Air bubbles will cause the "sneeze". I had a similar problem with an old 80hp. Temporarily put a clear piece of fuel line on...you'll be able to see the bubbles.

If your plugs are sooty....check to make sure that you have the CORRECT plugs. Then check to make sure each cylinder is getting PROPER spark with an adjustable spark checker. If you do a lot of trolling a low speeds...you may end up needing a hotter plug to fight the soot.

 

[emdsapmgr]

If the plug is dry, be careful! Possible that the cylinder is not getting any fuel-and that also means no oil. I'd probably remove the carb and pull the jets on the side of the carb that feeds the dry cylinder. Possible debris in the jets, restricting fuel and creating the lean sneeze condition. Each jet throat has 3 jets, mains, mid and idle. Get them out and visually inspect all 3 of them. Also, the idle passages in the upper carb body tend to restrict over the years. You may want to re-clean all the passages in that carb.