99 MODEL 4 STROKE MERCURY 40

[eskimo man]

WHATS THE PROBLEM WHEN MY MOTOR IS BOGGING AT ABOUT HALF THROTTLE AND KIKCKS-IN AT NEAR FULL THROTTLE?

 

[WillyBWright]

Re: 99 MODEL 4 STROKE MERCURY 40

Maybe some varnishing. It doesn't take much on 4-strokes. Add a Gumout sort of thing to the gas and hope for the best.

 

[bleew0]

Re: 99 MODEL 4 STROKE MERCURY 40

I have a 30 four stroke I think it is the same with different carb setup but i have been having the same problem for a few years mine is a 1999 also. It recently got worse and now has compression issues. I am wondering if it may have been some kind of defect with head gaskett. I have cleaned carborators multiple times. I am about to check cause of current problem.

 

[b-boof]

Re: 99 MODEL 4 STROKE MERCURY 40

I have been having similar if not the same problems with mine. I rebuilt the carbs and it still had the issue of bogging mid throttle, but idling and full throttle it worked fine. I have spoke with a merc technician and he said I would have to sync the carbs to rule out anymore carb issues.