Rich/Lean

[Nick6954]

Could someone explain the Rich/Lean concept.<br />I have a 1967 Johnson 6hp. Is it better to run Richer or Leaner? Thanks for any help

 

[phatmanmike]

Re: Rich/Lean

if you run lean, you melt pistons and blow powerheads.....<br /><br />if you run rich, you foul your spark plugs......<br /><br /><br />what would you rather be on the side of ....<br /><br />run at 50:1 and youll be good

 

[Nick6954]

Re: Rich/Lean

Thanks phatmanmike.

 

[JB]

Re: Rich/Lean

2 strokes are very sensitive to fuel/air ratios, Nick.<br /><br />Assuming that you have a proper amount of oil in the fuel mix, which is as PMM says.. .50:1:<br /><br />If the mix is too much air and not enough fuel the engine will sneeze at idle speeds and run too hot combustion chamber temps. If you are lucky it will simply bog down and refuse to run. If you are not lucky it will melt a piston and or sieze.<br /><br />If there is too much fuel and not enough air the engine will burn too much fuel, lose power and "burble", which old guys like me call "4 cycling", and eventually get clogged with carbon and/or foul your plugs.<br /><br />My choice is to run the smaller JohnnyRudes slightly toward rich, but not rich enough to get into 4 cycling. Clean and gap plugs and decarbonize regularly. You might get less power that way, but you will get much longer engine life.<br /><br />Good luck.

 

[Nick6954]

Re: Rich/Lean

Thanks JB,<br /> One last question: the plugs i have i think are cj6, i believe with out going out in the snow and looking, do not have the normal (tap?) that you would see on a car or lawn mower motor. Is thier a way to gap these types of plugs??<br />thanks for your time and advise

 

[walleyehed]

Re: Rich/Lean

That should be a J6C, it's a normal looking plug, gapped at .030. Now there IS a CJ6, but that is an incorrect plug...should be a short little plug if it's a CJ6.

 

[Paul Moir]

Re: Rich/Lean

For instructions on setting that mixture control, read Joe Reeves post:<br />Post, click here.<br /><br />That's for a different engine, but the adjustment is the same as yours. (You only have one, the idle mix control, right?)