Engine Trouble

[smmurphy]

Can any one help me out here? I have an '85 Merc 2cycle 4 cylinder 50 hp engine, It starts and runs fine in the drive way, but as soon as I get it out on the water it doesn't idle well and bogs down over half throttle.

[VMS]

time for Carbs to be cleaned and rebuilt.

My father had the same motor for years...ended up having the carbs redone every other year or so...but he did not use it much, and let the motor sit with unstabilized gas in it all summer..

Steve

[eurolarva]

From your post on the driveway you mean with water muffs?. If so take your spark plugs out and look at them. Do they both look as dirty as the other one? Is one clean and the other dirty? A motor will sound normal running on one cylinder and with water muffs there is no back pressure. When the motor is in the lake the dead cylinder becomes more obvious and will not run under load. It could be a dirty carb but I would do a compression and spark test on it first.