Low Compression/Cylinder Wash

FreeBeeTony

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May 15, 2002
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After troubleshooting what I thought was a "No Spark" condition.........It looks like I flooded the engine and created cylinder was.
I checked the compression yesterday (1 cylinder in each bank) and found #7 = 80PSI and #4 60PSI.

How can this be corrected? I have read about adding oil in the cylinders and cranking it over.
Can I add MM oil down the carb so I don't have to remove the plugs again? Not a fun time!!
 
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interalian

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I'd oil it up and see. You could use a fogging oil while cranking if removing the plugs is such a pain.
 

Scott Danforth

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not sure compression that low can be fixed with snake oil in a can

I would be pulling the motor
 

FreeBeeTony

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not sure compression that low can be fixed with snake oil in a can

I would be pulling the motor

Not really what I want to hear..........
Gonna try putting some MM oil down the carb tonight, crank it a little and let it soak till tomorrow and see what happens.
 

Scott Danforth

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the problem with pouring it down the carb, the cylinders that need it wont get it, the two lowest cylinders will. unless you pour enough to flood the entire engine (and hydro-lock it) you wont get any into the cylinders you want.

your going to have to pull the plugs at a minimum for those cylinders.
 

FreeBeeTony

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Went down to the boat yesterday.........still did not start.
​Am I under a time constraint? Does it matter if it sits till the w/e?
 

FreeBeeTony

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Not sure if I posted a pic of the plugs I removed.......here they are.
Not sure why they show signs of rust.

20170709_153521_HDR_resized.jpg
 

Bondo

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Donno Tony,... Appears ya might have something rather serious goin' on,...

How old are the manifolds/ risers,..??
 

Lou C

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Tony I saw your other thread, about burning oil, I'm wondering if you had some water intrusion via the risers. You have full closed cooling? If the plugs showed rust then I'd really want to see what those risers looked like. Although 2 years even in our salt pond should still be good.

​What I would have done, is pull all the plugs, ground the ignition, hook up a remote starter switch and crank her over. Look and see if you have any water droplets coming out the plug holes. Then to loosen things up I'd spray fogging oil in each cyl via the plug hole and then crank it a few times, then spray some more and replace the plugs. Then drain the risers, and remove them.
 
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