1998 115hp Mercury won't accelerate past 3k rpm under load.

[Wrapitupdave]

I have a 1998 115hp Mercury that starts and idles fine. It runs up to about 3,000 rpm fine. Then it will not accelerate beyond 3k. It will run at that speed or below and occasionally it will cough and sputter a couple of times and go back to normal running great. I changed the external fuel filter and it did the same thing. I'm planning to try a new fuel line and bulb. But I suspect the 2 + 2 feature of this engine may actually be the problem and I don't have a clue how to troubleshoot this other than just parts changing. And on the 2+2 I don't know what parts are involved.

 

[jimmbo]

Start with the Basics, Does it have Spark on all 4 Cylinders? When I say Spark, I mean, can it jump a 7/16" gap? Next would be compression? Is fuel getting to all the carbs?
How old is the gas?

The 2+2 feature simply starves 2 of the cylinder s f sufficient fuel for the spark to ignite it. Once the engine is running fast enough for carbs to supply fuel from the off idle and Main circuits it is like any other carb and engine

How long have you owned this engine? If it has beenyours for a while, what was the Procedure you used when you put it away for the Winter?

Best Advice I can give, is to get a genuine Mercury Service Manual for that Model of engine

 

[gbrowne9]

if all that other stuff is ok check your stator.if it,s not putting out enough power at high speed the engine won,t rev up.