Blow by=normal?

nola mike

nola mike

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Joined
Apr 22, 2009
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5,072
Just got finished installing my rebuilt Carb because of some issues I was having. Boat is now running great. When I was adjusting the idle/mixture with the flame arrester off, I noticed some blow by through the valve cover. Not too noticeable with it on, but there if I looked for it. Seems like exhaust gas. Coolant/oil levels normal. Compression is 140-150-155-140. I've never noticed this before, but who knows if it was there. Is this something to be concerned about in a 26 year old engine, or would you expect some degree in an old engine? Should I pursue further testing?
 
F

Failproof

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Sep 26, 2011
Messages
273
Re: Blow by=normal?

Every engine has blow by. If compression was good, and leakdown was good, would not worry. Make sure your breather valves are clean and breather lines are connected to arrester.
 
nola mike

nola mike

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Joined
Apr 22, 2009
Messages
5,072
Re: Blow by=normal?

Didn't do a leak down. Would that tell me anything if the compression is normal?
 
cr2k

cr2k

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Mar 19, 2009
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3,730
Re: Blow by=normal?

Would tell you if there are any bad spots in the cyl walls.
 
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