Johnson 6 - poor running/stalling

[aelangford]

I have an old Johnson 6 (approx 1979) which starts OK but as it warms up "surges" and stalls. i.e. with throttle held at constant position (near to high speed running position)the revs go up and down, sometimes stalling. Any ideas please? Also, what are the correct plugs to use?

 

[alcan]

Re: Johnson 6 - poor running/stalling

Hi Tony<br />Please post the model # of this unit, this way we call tell what motor you have and the tpye systems it uses. First you need to test the compression. If that checks ok, it sounds like your motor is starving for fuel. Check the vent on the tank, it must be open. Test fuel pump. remove and clean/adjust carb.