2000 Johnson 130hp 2-stroke spitting, sputtering

[BluefishBuster]

Hey guys. I'm having an issue with my 130HP 2-stroke. After warm up and running wide open, if I slow to minimum throttle in gear, I get a coughing, spitting, sputtering, whatever you want to call it. Sometimes the motor will even stall out from it. It's almost like it's misfiring but I'm thinking it has more to do with lean fuel mixture. This ONLY happens at slow forward ... at high speed, everything seems to be fine. Reading up on it in my shop manual, the most likely cause seems to be a thermostat problem with the engine running too cool. Under this condition, fuel will puddle in the crankcase causing a lean condition. So I'm thinking I need to change out my thermostats (vernatherms actually). I'm having a hard time determining whether I need a 105 degree thermostat or a 143 degree thermostat for this engine. Does anyone know where I can find this info? The Clymers manual is of no help on this.

Thanks in advance for your help,
BluefishBuster

 

[Dhadley]

Re: 2000 Johnson 130hp 2-stroke spitting, sputtering

436195 is the part number for the vernatherm.

 

[Walker]

Re: 2000 Johnson 130hp 2-stroke spitting, sputtering

And check your recirculation valves. They are supposed to aid in keeping the excess fuel out of the crankcase.
Let it stutter and stumble for a while and then pull the sparkplugs and see what they look like. Fuel puddling in the back of the intake mainfold will give you black soot fouled plugs, usually the bottom plug.

 

[reeldutch]

Re: 2000 Johnson 130hp 2-stroke spitting, sputtering

why dont you check you operating temp.

should be around 142 if i'm not mistaken.

when you come down from wot and the moter starts to sputter,
hit the primer for second see if she picks up shortly.

that would indicate a lean carburator.