95 50 HP tops out below 3K RPM

[Jrzvike]

I have a 95 Evinrude 50 HP outboard that I have to remove the plugs and blow dry the cylinders with a blow dryer to start. Once started, it runs fine if it is warm out (60+ degrees). Will run all day, restart no problems. If it is cool out or the water is cold, the motor will not run over 3000 RPM. If I open the throttle, it tops out at 3K RPM and runs approx. 5-10 MPH. If I leave it wide open, sometimes it will jerk violently and begin running normally. Generally, it will run normally the rest of the day. If it is really cool out (45 degrees and below), it will not jerk and run normally, it will stay topped out at 3K RPM. I've replaced plugs, wires, conditioned fuel, fuel filters, seperators with no luck.

 

[Jrzvike]

Re: 95 50 HP tops out below 3K RPM

I might add, when the motor is running properly, it runs like a top. No misses, smooth sounding and starts immediately. No method to the madness though...

 

[tashasdaddy]

Re: 95 50 HP tops out below 3K RPM

have you checked compression? spark? when were the carbs last disassembled and cleaned, and adjusted. it only has one adjustment, slow speed, starboard side on carb.

 

[5150abf]

Re: 95 50 HP tops out below 3K RPM

As TD said start with compression then spark with an actual spark checker, putting the plug on the head won't tell you anything, if those check out try starting the engine and squirt alittle gas into the carbs one at a time, if the engine is suddenly "fixxed" you have a clogged jet, you have the classic symtoms.

For what ever reason they put the high speed jets at the bottom of the float bowl so the tinniest amount of crap will plug them up and cause what you are describing.

They are behind the drain scew on the float bowl and you will need a really skinny screw driver to get them out.

 

[kenmyfam]

Re: 95 50 HP tops out below 3K RPM

Yep, basic health check before moving on.
My 2 cents.

 

[Jrzvike]

Re: 95 50 HP tops out below 3K RPM

Thanks all! I will examine the carbs and let you know how it goes...