"I have an '86 mercruiser
"I have an '86 mercruiser 260 that continually surges between 800 and 900 rpm in neutral and sounds like it wants to stall briefly as it dips down to the 800 range. There wasn't a manual with this boat when I bought it, so I'm just kind of flying blind with only a little working knowledge of boat engines. So far this season I've put in new batteries, new fuel filter, new starter solenoid, cleaned electrical connections, and replaced oil. I had about 25 gallons of gas that sat in it over the winter months. Poured some Seafoam cleaner down into the tank and dumped a few gallons of fresh gas on top of it hoping that would smooth things out, but so far it hasn't. Could it be a simple matter of completely topping off the tank with fresh gas? Holds about 100 gal. Any ideas what else might cause this?"
"I have an '86 mercruiser 260 that continually surges between 800 and 900 rpm in neutral and sounds like it wants to stall briefly as it dips down to the 800 range. There wasn't a manual with this boat when I bought it, so I'm just kind of flying blind with only a little working knowledge of boat engines. So far this season I've put in new batteries, new fuel filter, new starter solenoid, cleaned electrical connections, and replaced oil. I had about 25 gallons of gas that sat in it over the winter months. Poured some Seafoam cleaner down into the tank and dumped a few gallons of fresh gas on top of it hoping that would smooth things out, but so far it hasn't. Could it be a simple matter of completely topping off the tank with fresh gas? Holds about 100 gal. Any ideas what else might cause this?"