Lou McGoldrick
Member
My question is if I adjust the lo idle screw too lean to prevent fuel in the crankcase can this cause a problem other than running poorly??
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Probably not. Engines don't "like" lean as it raises combustion chamber temperature and can cause detonation and pre ignition. But on an outboard with a working cooling system it's less of an issue at lower rpm.
However, your question creates more questions. If you're getting fuel dilution with a PROPERLY adjusted idle mixture, I doubt that leaning the idle out "too much" will solve your problem.
The 8hp should troll all day, every day at idle and shouldn't "load up" unless you NEVER open it up and clear it. Any outboard will develop carbon deposits if endlessly idled and carbon can cause incomplete combustion. And, incomplete combustion could be a reason for some oil contamination.
But the #1 culprit for fuel getting in the oil is incomplete combustion due to low engine operating temperature due to an inoperable or missing thermostat.
Good luck.