bad compression

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FLounder

power hungry
VIP
ran a compression test after doing a valve adjustment the other day. my engine is only 9.6:1 since its still the stock b20z block, but anyway its not good.... 190-165-145-200.

cant figure out what the problem is. oil and coolant both look ok. not smoking except a slight amount at high rpms. no soot on the bumper or even the tailpipe. plugs look fine. might be time to rebuild. or any chance it could be just the head gasket?
 

austin20110

Active Member
I dont have tooooo much experience with blown headgaskets but it doesnt seem thats what the problem is here... dont freak out yet
 

FLounder

power hungry
VIP
i did go back and check the valves again. they are spot on. i am a boat mechanic and i have adjusted a few valves before :D many 4 stroke outboards valves are similar to a b series honda. but yeah it could be rings i suppose.... im bummed
 

Magana559

The Warden
try adding some oil in the cylinders......not much but a lil.

try checking your compression before and then add the oil and check again.

if your compression rises after the oil then you have a ring issue if not......... then is somewere else.
 

GlassHeadlights

West West Yall
There is still a posibility that you tightened them down too tight, you could loosen them up so they're tapping and try that.

Tapping valves are better than valves that are too tight.


I'm also assuming you warmed it up before the test.


+1 on the leak down test.
 
Could possibly be a head gasket. If you look at the readings the 2 low cylinders are right next to each other. Only real way to find out is to leak down test it and figure out where your air escapes from.
 

austin20110

Active Member
Could possibly be a head gasket. If you look at the readings the 2 low cylinders are right next to each other. Only real way to find out is to leak down test it and figure out where your air escapes from.


good job on collecting what everyone else said and making it into one post
 
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