gas in the oil - Page 3

Pop Alexandra · 03-13-2024, 10:35 AM

Quote:

Originally Posted by element80

ive been sending oil samples to blackstone labs since bike was new...always had a little fuel in oil, i may be running a tad rich

Very interesting. I ought to also send some oil samples. I might be surprised of the result.
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Alexandra from lab analyzers

andyvh1959 · 05-01-2024, 06:13 PM

When you say "always a little fuel in oil" how much fuel are you talking? Until a bike engine is fully broken in, some oil consumption can be expected. Like a BMW flat twin taking up to near 20K miles before the rings really fully seal. But then the issue is most often oil getting into the combustion chamber, not gas getting into the oil. Could be other factors, like piston ring gaps aligned so when the piston is at BDC there is a direct gap to the crankcase for gas to get into the oil. Could be a scratch on the cylinder bore. Could be worn rings. Could be a fuel injection system issue.

Might be worth a compression test, and a cylinder leak down test to confirm everything from the bottom of the cylinders and up is as it should be.

05-01-2024, 06:13 PM	#32
andyvh1959 Advanced Member Join Date: Dec 2017 Location: Green Bay WI Posts: 768	When you say "always a little fuel in oil" how much fuel are you talking? Until a bike engine is fully broken in, some oil consumption can be expected. Like a BMW flat twin taking up to near 20K miles before the rings really fully seal. But then the issue is most often oil getting into the combustion chamber, not gas getting into the oil. Could be other factors, like piston ring gaps aligned so when the piston is at BDC there is a direct gap to the crankcase for gas to get into the oil. Could be a scratch on the cylinder bore. Could be worn rings. Could be a fuel injection system issue. Might be worth a compression test, and a cylinder leak down test to confirm everything from the bottom of the cylinders and up is as it should be. __________________ My $1200 Vulcan, to start from. Last edited by andyvh1959; 05-01-2024 at 06:17 PM.
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