oil mixture

[jeff6898]

1979 Evinrure 85hp 85999R

I been noticing my plugs are getting fouled with oil. I use a mixture of 50:1 like the book says. Seems like it might be to much oil though. Will it hurt to drop to 40:1 ?

 

[jeff6898]

Re: oil mixture

Sorry meant 100:1

 

[tx1961whaler]

Re: oil mixture

Unless you do alot of extended low speed trolling, the fouling problem is not caused by running at 50:1, and yes, you can damage your engine by running it at 100:1.
The things I'd look at are:
Compression
Spark (using a spark tester)
Decarb the motor
Spark plugs (Champion L77JC4 or QL77JC4, .030" gap)
Oil - Full synthetic at 50:1 is supposed to smoke and foul less

 

[samo_ott]

Re: oil mixture

try the next hotter plug...

 

[kenmyfam]

Re: oil mixture

Sorry meant 100:1

Do NOT use less than the recommended amount of 2 stroke oil. Very bad and potentially expensive idea. If you are fouling up constantly there is something else wrong.

 

[jeff6898]

Re: oil mixture

Compression is 140 139 140 140

Spark nice blue and jumps

Carbs just been rebuilt this time I even put in brand new idle jets and floats.

using Champion QL77JCY gapped at .030

NOw we did run around the lake at idle for about 15 minutes and then another 5 or done at the boat ramp. We just wanted to see how it ran at idle since before the carb rebuild it wouldn't stay idling.

 

[a70eliminator]

Re: oil mixture

Every two cycle engine I've seen get some oil on the plugs, if they're fouling out then you've got problems. When i check my plugs they have a nice brownish tan insulator, the electrode bridge is dry and I always see oil residue around the perimeter, it sounds normal to me. Are they really being fouled, a fouled plug will cause a misfire.