jason_thompson
New member
"This one has me stumped and h
"This one has me stumped and have spent alot of time under the hood trying to figure it out.
Last season boat ran great except at wot. Peak RPM's was 5,000. It would run at 5,000 then drop to 3,000 for a second then back to 5,000. It would do this indefinitly untill I backed off the throtle to say 4,700 rpms. Then it would just purr. The only thing that improved this rpm fluctuation was to pump the primer bulb so I figuered I had a fuel pump issue.
This spring I took it out for the first time and it did the same thing. The next trip out it ran flawless at 5,000 rpm's untill I stopped to fish for a bit. Started the motor back up and at WOT it will only turn 4,000 rpm's.
Pulled the plugs. Had a wet one so I changed it. Did not fix the problem. I replaced the coil and spark plug wire. Still not fixed. Still the same wet spark plug. I replaced the power pack and replaced all the spark plugs and still the same problem. All spark plugs are getting spark. I checked throtle linkage, checked the fuel tank, checked the fuel filter. I even tried pumping the primer bulb and this only makes it loose rpm's. Around 200 or so.
It seems to run on all four at idle up to 3000 or so. That is when it drops the one cylinder. It kinda acts like it is trying to clean out. I know I should check compression but that was done last year by the local evinrude shop at they were all good.
Is it possible to have a stator/sensor issue or does this sound like a fuel delivery issue? Any suggestions?"
"This one has me stumped and have spent alot of time under the hood trying to figure it out.
Last season boat ran great except at wot. Peak RPM's was 5,000. It would run at 5,000 then drop to 3,000 for a second then back to 5,000. It would do this indefinitly untill I backed off the throtle to say 4,700 rpms. Then it would just purr. The only thing that improved this rpm fluctuation was to pump the primer bulb so I figuered I had a fuel pump issue.
This spring I took it out for the first time and it did the same thing. The next trip out it ran flawless at 5,000 rpm's untill I stopped to fish for a bit. Started the motor back up and at WOT it will only turn 4,000 rpm's.
Pulled the plugs. Had a wet one so I changed it. Did not fix the problem. I replaced the coil and spark plug wire. Still not fixed. Still the same wet spark plug. I replaced the power pack and replaced all the spark plugs and still the same problem. All spark plugs are getting spark. I checked throtle linkage, checked the fuel tank, checked the fuel filter. I even tried pumping the primer bulb and this only makes it loose rpm's. Around 200 or so.
It seems to run on all four at idle up to 3000 or so. That is when it drops the one cylinder. It kinda acts like it is trying to clean out. I know I should check compression but that was done last year by the local evinrude shop at they were all good.
Is it possible to have a stator/sensor issue or does this sound like a fuel delivery issue? Any suggestions?"