Compression Test After Winterization

FreeBeeTony

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Winterized my 350 a few weeks ago........fogged pretty well w/ MM oil.
Would it be a bad idea if I performed a compression test in the next month when I replace the plugs?
Would it negate the fogging procedure?

Tony
 

tpenfield

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Compression tests are best done when the engine has been warmed up to operating temperature. So, that will negate the fogging and other winterization that you may have done.
 

Bondo

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Winterized my 350 a few weeks ago........fogged pretty well w/ MM oil.
Would it be a bad idea if I performed a compression test in the next month when I replace the plugs?
Would it negate the fogging procedure?

Tony

Naw,.... Not til ya actually start it,....

Yer compression readin's might run high, from the excess oil,...
 

FreeBeeTony

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Reason I want to do it when I replace the plugs is because they're not too easy to access and don't want to remove them more than once.
 

Bondo

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Reason I want to do it when I replace the plugs is because they're not too easy to access and don't want to remove them more than once.

Ayuh,.... Happy turkey day Tony,... Go for it, it won't hurt a thing,.... ;)
 

FreeBeeTony

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Same to you Bondo.......hopefully we get a little bit better weather over the w/e.
 

bspeth

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I would fire it in the spring with the old ones,get it to temp and swap/comp test.Burning the oil will probably dirty the electrode a tiny bit.
 

thumpar

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The compression test would not be accurate if you did it with the fogging oil in the cylinders. Just wait. I will be doing plugs, wires, cap and rotor this Spring.
 

JoLin

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If you're trying to get a read on the engine's general health, then go for it. You're interested in seeing reasonable compression, and the 'spread' from low to high. I'm troubleshooting a running issue on a 3 cylinder Yamaha outboard. Getting back to basics, I wanted to make sure I didn't have a blown head gasket, busted ring, holed piston or scored cylinder. On a stone cold engine with 35 deg. ambient outside temp I got readings of 95-100-100 lbs. across the 3 cylinders. It ain't like new, but it's good enough. Seeing that was sufficient for my purpose.

If you really want to know the actual compression for each cylinder then wait like the others said.

My .02
 
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