I think your 40:1 makes sense for hard running. Back in the '70's we used
to run 24:1 in our dirt bikes. Just remember, heavy oil mix takes away some
from your fuel. Too much oil will make it run lean (since the oil doesn't
burn, it takes the place of the gas). If your plugs look good,
compression's good, my bet would be to do exactly as you are. I troll a lot
with my 200 merc and do tend to foul the plugs somewhat (with 50:1).
LD

"Gudmundur" wrote in message
...
Any of you folks ever ruin an outboard because of stuck rings or carbon
under the rings?

Was it from long hours of low speed trolling or high speed use?

I tend to run my engine at 40:1 with OMC XD30 and I was wondering if
perhaps that is bad for my rings compared to 50:1 mix. I run the engine
pretty hard pulling a skier often, amounting to about 50% of the engine
hours. I can turn the engine easy enough with my hands on the flywheel
and the compression is balanced at about 120 each. I am really just
trying to get the most life out of this motor and not hurt it.

The motor is a 1981 3cyl 70hp Evinrude.

Anyone want to share "wish I wouldn't have done that" stories?

TNX guys