For Mercury Bob

[Rod Orieux]

My brother has a 2002 mercury 115 2 stroke that says Tracker on the cowling. The boat is a 2002 nitro 188 Fish/Ski and happens to be my brother's first boat. He took it out for the first time yesterday and the motor was acting a little wierd. We were trolling at about 1600 rpm and at about one minute intervals a vibration like that of a pump could be heard coming from the engine and could be felt throughout the boat. This noise and vibration would last for about 30 seconds. I know it's not a lot to go by but if you have any ideas it would be appreciated. Sorry for no serial.

 

[Bob Bourget2]

That series of engine is designed with a "concept 2+2". The motor will run on the the top two carbs [there are four}, until approx 1600-2000 rpm, where the other two carbs will start to operate, controlled by jetting, accelerator pumps and timing. If you allow the motor to linger in the range, all kinds of strange things occur. Try to accelerate through it quickly and see if there is in fact an issue.....me thinks not.....

 

[Rod Orieux]

Thanks Bob. You set my mind at ease.