115 Merc cutting out

[Radioactive]

Had the boat out today and the motor started acting up. '89 Merc 115 oil injected. When I first tried to give it full throttle it would only rev to about 1,500 rpm. I slipped it in neutral and revved it a couple of times and it seemed ok, so tried again and it did just fine. Got about half a mile down the lake and it did it again. Idled down and then it took full throttle ok again. Ran ok back to the dock until I idled down in the no wake zone then it sounded like it was missing on one or possibly two cylinders. Did this once before several days ago, but I thought it might have picked up water or a bit of crud in the gas. I used stabilizer over the winter and have re filled the tank recently with fresh fuel
Had new tuneup last Summer and has less than 10 hours since

Any ideas appreciated

[cutbait101]

take a fuel sample in a glass jar,to check for water.check fire on all cylinders and do a compression check.if everything is good i would look at fuel bulb and fuel pick up in tank to make sure it is not stopped up.good luck

[DonDon]

Runing at full throttle it was acting like it was wanting to cut out abit. A friend of mine said to run some seafoam through it. Could be carbon buildup

[Radioactive]

Thanks cutbait and dondon.

I have already checked all the fuel lines and drained the tank. I did get some crud from the bottom but no water. I will be changing the fuel filter soon and will post the results

[Bassky]

Sounds like it could have an air pocket in the gas line. I have a 81 Merc 115 and have encountered the same problems at times. You could be getting air in the line between the tank and the inlet to the motor. It could be your prime bulb is losing prime after a while. May need to replace or check clamps in or around your fuel lines, be sure they are tight.
Bassky

[brushnjigs]

Use a portable tank with new fuel and see if that is the problem. If not you could have a coil going bad. I have had bad gas and also a coil do the same thing

[Radioactive]

Took her out today and no issues. I had already drained the gas tank and checked all fuel lines and connections. Pulled the plugs,cleaned and re gapped them even though they looked like new. Refilled with fresh fuel and dumped in a bottle of carb cleaner for good measure.
Not sure exactly what the problem was, but it didn't re surface today on about 6 or 7 miles total run. Also tried various throttle settings just to see if it made any difference.
Next time I go into town I will pick up a new fuel filter as it looks like it has the original one from the factory as the clamps are those funky squeeze together types that can't be re used.

Thanks to all that posted suggestions