'ghost' changing rpms

[Dick Sorensen]

On the 2011 maiden voyage my 185 hp 229 cu in merc ran great.....started on the third try....yea...not bad for a 1985 model..... as the morning progressed the engine started to increase by about 200 rpms....say running at 3000 the engine would then just increase to 3200....then about 1 minute later it would drop back to 3000...did this acouple of times....dropped the rpms to 2000 or so and it did it again....it would go up by 200 or so....Everything else seemed to be fine....did not give the boat a tune-up this year and the steering resevior was very low when I checked at the end of the run....Can anyone help....

 

[dubs283]

Re: 'ghost' changing rpms

sounds like maybe a piece(s) of debris in the float bowl periodically covering a passage

 

[Art Bernard]

Re: 'ghost' changing rpms

Take a look at your throttle lever, it may be loose and vibrating up or down depending how it's mounted. I have a similar issue with mine. My throttle box is mounted on the side of my center console at a 45deg angle and sometimes it slips back and reduces rpm/speed. With yours going up and down though, it might also be timing slipping a bit, maybe something loose? Just a guess, hope ya figure it out, nobody likes a ghost in the machine