GAS OIL RATIO FOR 80 MODEL 25 JOHNSON

[DANNY II]

I JUST BOUGHT A USED 80 MODEL JOHNSON 25 HORSE AND THE PERSON I BOUGHT IT FROM ALSO BOUGHT IT USED AND NEVER USED IT, SO HE COULDN'T TELL ME THE GAS TO OIL RATIO. I ASSUMED IT WOULD BE 50:1 HOW EVER IT HAS BEEN FOWLING OUT MY PLUGS. I WOULD GO STRAIGHT TO 100:1 TO SEE IF IT RUNS RIGHT BUT I WOULD HATE TO BURN UP THE MOTOR. DOES ANYONE KNOW FOR SURE THE RIGHT RATIO?

 

[roscoe]

Re: GAS OIL RATIO FOR 80 MODEL 25 JOHNSON

50:1 tc-w3 rated oil<br />take your pick between regular or synthetic.

 

[CATransplant]

Re: GAS OIL RATIO FOR 80 MODEL 25 JOHNSON

What plugs are you using in that 25hp? The wrong ones will certainly foul...or worse. The correct plug, according to the factory is a Champion L77J4.

 

[DANNY II]

Re: GAS OIL RATIO FOR 80 MODEL 25 JOHNSON

Originally posted by CATransplant:<br /> What plugs are you using in that 25hp? The wrong ones will certainly foul...or worse. The correct plug, according to the factory is a Champion L77J4.

WELL IM USING A CHAMPION L77JC4. BUT, WHAT IS HAPPENING TO THE MOTOR IS THAT AFTER I CHANGED THE PLUS RECENTLY IT OPERATED FINE FOR A LITTLE WHILE BUT THEN STARTED "CHOKING DOWN" AND RUNNING LIKE IT WAS ONLY FIRING ON ONE CYLENDER. AT LOW SPEED OR IDEL IT SEEMED FINE BUT WHEN I TRY TO OPEN HER UP SHE "BOGGS DOWN" AND WONT RUN RIGHT. WHICH IS WHY I CHANGED THE PLUGS TO START WITH.<br />BEING SOMEWHAT INEXPERENCED WITH OUT BOARD REPAIR I WAS JUST SPIT BALLING WITH THE GAS TO OIL RATIO BEING WRONG, I WAS HOPING IT WOULD BE THAT SIMPLE ANY WAY. SO WHERE DOES THAT LEAVE ME WITH POSIBILITIES FOR THIS PROBLEM?

 

[rottenray6402]

Re: GAS OIL RATIO FOR 80 MODEL 25 JOHNSON

I would bet on the carb being out of adjustment and running way rich.

 

[DANNY II]

Re: GAS OIL RATIO FOR 80 MODEL 25 JOHNSON

Originally posted by rottenray6402:<br /> I would bet on the carb being out of adjustment and running way rich.

WELL NOW THAT YOU MENTION IT I DID HAVE TO RUN IT WITH THE CHOKE OUT ALL THE WAY THE LAST TIME I TOOK IT OUT BECAUSE WHEN I PUSHED IT IN IT WOULD KILL IT.<br /><br />ALSO THERE IS A RICH TO LEAN ADJUSTMENT IN THE FRONT OF THE MOTOR BEHIND THE COVER. WHERE SHOULD I HAVE THAT SET?<br />IT'S JUST A KNOB WITH ARROWS POINTING WHICH WAY FOR RICH AND WHICH WAY FOR LEAN.

 

[bubbakat]

Re: GAS OIL RATIO FOR 80 MODEL 25 JOHNSON

Or a bad fuel pump or sucking air at one of the connections

 

[shebe3]

Re: GAS OIL RATIO FOR 80 MODEL 25 JOHNSON

That "rich to lean ajustment knob" is for low speed fuel adjustment only. High speed has no adjustment, it's a fixed jet. Bubbakat is probably right, you have an air leak somewhere in the air intake system. Could also be the stuffer block gasket.