carb trouble maybe?

[surfbp]

I am having trouble with my 1993 90hp Merc. Its hard to start.. once its started you idle it down and it stalls. Sometimes it stays running but once I get going fast it lags really slow off an on. I noticed that fuel it being squirted out of th fuel vent on the top carb. I think it maybe the float or the pin is clogged from the enthanol in the fuel. It also seams that its blowing more smoke then normal.... it oil injected so maybe no fuel to the top cylinder?? only oil? Any help would be greatly appreciated. I just don't want to have to pull the whole carb apart to clean if thats not the problem.
Thanks

 

[Windykid]

Re: carb trouble maybe?

Sounds like a sticking float.

 

[Chris1956]

Re: carb trouble maybe?

Like Windy said. It sounds like the upper inlet needle is sticking open. it could be dirt in the inlet needle or seat, or a sticky float. Best to take the carb apart and clean it out.


Now if the top carb floods, you will have difficulty idleing smoothly, and may have high speed issues as well. On the oil injection system, the oil is usually mixed with the fuel at the pump. If you are flooding the top carb, you could be burning extra rich, whcih translates into extra smoke.

 

[hkeiner]

Re: carb trouble maybe?

Removing the carbs for cleaning is the best solution.

However, if you want to try something that is easier to do before you take the carbs off, you might try running a strong mix of Seafoam through your carbs. My preferred way is to mix 2 cans of Seafoam with 2 gallons of fuel in a 3 gallon portable tank and than connect the tank to the motor. Run the motor for 10-15 minutes at idle and then turn it off for 10-15 minutes. Repeat. Leaving the Seafoam/fuel mix in the carbs overnight is even better. Run the mix through the carbs at idle until you use up the mix. Add fresh fuel to the portable tank and see how it runs. You may need to run a second batch of strong mix to see results. This process will also decarb your motor as a side benefit.

The above method worked for me when I had similar carb symptoms. Of course, it won't help if your problem is due to a misadjusted or broken parts. It can only possibly help with sticking/gummed parts.