Low Compression After Overhaul

Hooty

Rear Admiral
Joined
Oct 2, 2001
Messages
4,496
Re: Low Compression After Overhaul

Hey, no problem. You and WildeOne kinda ask the same thing. I'm like everybody else, I can't see the engine runnin' with compression that low but ...<br /><br />c/6<br />Hooty
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: Low Compression After Overhaul

I'm with many of the above posts.Recheck compression using a known good guage.If your readings are still low ,I would suspect a misapplication of the rings(ie end gap).If a few broke on a cylinder or two the readings would not be consistent but rather sporatic.It would be nothing short of a miracle for this engine to run under load in water with 30psi compression across the board.Even a shallow crosshatch IMO would not cause readings that low ,and at worst would delay the seating of the rings as long as the bore is concentric.
 

ledgefinder

Ensign
Joined
May 2, 2002
Messages
916
Re: Low Compression After Overhaul

Is it possible he's got the wrong pistons in there - loopers with no domes?
 

Hooty

Rear Admiral
Joined
Oct 2, 2001
Messages
4,496
Re: Low Compression After Overhaul

I think chip51maker figgered what was wrong, but he's not gonna tell. ;) <br /><br />c/6<br />Hooty
 

CFronzek

Petty Officer 2nd Class
Joined
Aug 11, 2002
Messages
118
Re: Low Compression After Overhaul

Check your compression tester. It should have a valve core with a light weight spring in it. If someone has accidentally installed a core intended for a tire (it is identical except for the spring which is much heavier) the gauge will read low.<br />Charlie
 

wilde1j

Vice Admiral
Joined
Apr 15, 2002
Messages
5,964
Re: Low Compression After Overhaul

Hooty, I think your right ... the silence is deafening!
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: Low Compression After Overhaul

This suspense is killin' me!!!!!! Chipmaker...WHAT'S UP!!
 

8up

Petty Officer 3rd Class
Joined
Nov 2, 2003
Messages
98
Re: Low Compression After Overhaul

This is like reading a book with the last chapter torn out!
 

chip51maker

Recruit
Joined
Nov 10, 2003
Messages
4
Re: Low Compression After Overhaul

Good morning,<br /> I appreciate all of your help and suggestions. As far as a time line, I rebuilt this motor last July and have never been really satisfied with its performance. I was discouraged and did not really know what to do. Only recently did a friend suggest that I try an "Online Forum" to get help from others that do this stuff everyday.<br /> Again thank all of You for your help and please accept My apology for not responding in a timely manner.<br /> As for the motor, I have found that the crankcase halves are leaking due to the fact that I did not use the proper "Crankcase Sealant"<br />I believe that the crankcase leaking (I can see 2 places that has blown out) for sure explains the less than desireable performance. All of this time I thought that I had an ignition problem. I have not addressed the compression problem yet but I did put the incorrect valve core in my compression gage. Hopefully the compression is acceptable and just my readings are wrong.<br /> I will keep you posted as things develop. It will be several weeks for sure. <br />Thanks <br />H
 

wilde1j

Vice Admiral
Joined
Apr 15, 2002
Messages
5,964
Re: Low Compression After Overhaul

Make sure the halves are absolutely clean and wipe the mating surfaces with trichlor or other good degreaser before applying Gel Seal and you should be fine. Glad the gauge was probably wacked.<br />Keep us posted on how you're coming along.
 
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