Mercury V-200 engines spits at idle

[usg5071]

I have a problem with my 1979 Mercury V-200. Had the boat 8 years with little issues until last year. The usual has been checked (i.e. Compression-plugs) and even a trip to the shop.

It sputters/spits at idle but runs well open throttle (although i think it's lost some of it's out the hole punch). It spits and usually dies unless you put it into gear right away and pull away.

I believe one of the coils were replaced but I'm hoping for some suggestions.
thanks

eddie in PA

 

[hkeiner]

Re: Mercury V-200 engines spits at idle

Some basic checks include using a spark tester to confirm a good spark on all cylinders and using a compression gauge to confirm good compression on all cylinders. Another test is to adjust the carb idle jets out or in a 1/4 turn at a time to see if that helps. If it does not, return the idle jets back to their original position. Lastly, squeeze the fuel bulb during idle to see if that helps it idle better. If it does, perhaps the fuel pump is failing or a carb's idle circuits are gummed up. Doing the above tests and reporting back on what you found will help narrow down the problem and probably get you some more responses.

Cleaning the carbs is never a bad idea if it has not been done for a long while or if the motor is not used for extended periods of time without Stabil or similar product in the fuel.

 

[j_martin]

Re: Mercury V-200 engines spits at idle

You're probably describing what's called a "Lean sneeze". It's caused by the idle fuel mixture being a little lean.

Try running a little tune up fuel additive of some kind through it. If it doesn't fix it, you'll have to go through the carbs and clean out the winter deposit of varnish and crud.

hope it helps
John