Mid range stutter, 95 Evinrude 9.9

[Jim311]

I attempted to do some scalloping on the 4th in Steinhatchee but my motor started to stutter and stumble intermittently in the middle of it's powerband. At wide open it didn't seem to have major issues, but it would still stumble once in a while. We stayed close to shore not wanting to get stranded. On the way in a sea breeze kicked up and I had to stay in the low/middle range of the power band. The motor crapped out close to the ramp and didn't want to easily restart. I trailered it home and it sat for about 24 hours before I had time to look at it. I pulled the plugs last night and they seemed wet with fuel. Could a stuck carb float cause these sorts of symptoms? The fuel bulb was firm and squeezing it while having this issue did not seem to change anything, so I'm not thinking it's an air leak in the fuel line.

 

[oldcatamount]

Re: Mid range stutter, 95 Evinrude 9.9

If it runs a high speed and runs at low speed, it's probably not a carb issue. I'd suggest doing a spark test with an air gap tester. Have a look at the plug wires and the wires from the ignition coils. Replace the plugs and be sure to gap them right at .030. Are you running fresh fuel?

 

[Jim311]

Re: Mid range stutter, 95 Evinrude 9.9

As far as fuel, I topped it off at a gas station on the way to the beach. It ran perfectly fine on the fuel that was in it about a week ago prior to the top off. I also filled up my truck at the same gas station and it is running fine so I don't suspect poor quality fuel. Some new plugs wouldn't be an expensive thing, although these ones are only about a year or a year and a half old, it probably wouldn't hurt. I also have a new coil sitting in the garage that I've just been too lazy to put on. The power pack is almost new. I agree that it seems weird that it will idle okay and run wide open fairly well, but have problems in the mid range.