54 cd-10 5.5hp how to tell if rings and pistons are bad?

[Ray2]

had 30 psi on both pistons, put motor horizontally poured about 2oz in each cylinder let set for over 8 hrs.sanded head on flat glass until shiny smooth, put new head gasket on , checked pressure again and still 30/30 hooked gas back up pulled and pulled no start,pulled plugs shot air in and put unoiled gasoline in both cylinders and it fired right up and ran for about 4 or 5 mins.and then died [see prev posts] checked again still at 30 psi on both,so pulled plate off side and see some scoring but not anything deep,dont see any carbon on the rings,cylinder walls looks good ,nothing deep, so how would i know whats bad?will also sand head again,or should i take it to a shop and have them plane it,this is my first time doing this so i dont know thanks for the advice.

 

[HighTrim]

Re: 54 cd-10 5.5hp how to tell if rings and pistons are bad?

Check the rings for bounce with a small screwdriver.

I would find it very odd that both sets of rings are worn equally like that . Sure sounds like an issue in the head or gasket between the cylinders. OR a bad gauge.

 

[Ray2]

Re: 54 cd-10 5.5hp how to tell if rings and pistons are bad?

thanks for the quick responds,checked rings with small screw driver,all six rings have spring in them,when you push one down a little gas comes out from under them, sanded head clean again to shiny clean,took strait edge[metal ruler} and in some places looks like maybe .002 off,is that too much?also going to get new head gasket,does it matter which side out? and should i put a little grease on it? i took some pictures but turned out bad,no deep scratches on pistons or walls. many thanks...

 

[MarvK]

Re: 54 cd-10 5.5hp how to tell if rings and pistons are bad?

Had a similar problem with my '56 CD-13. Turned out to be the head gasket blown between the cylinders. There seems to be a right and wrong way for the head gasket to go on. Pay attention to the top corner even though it looks symmetrical.

Marv

 

[F_R]

Re: 54 cd-10 5.5hp how to tell if rings and pistons are bad?

Forgive me for asking, and no insult intended, but how are you checking the compression? Are you pulling it until the pressure doesn't rise any higher? (You should). Other than that, it sounds like a bad gauge. Try another, just for kicks.

 

[MarvK]

Re: 54 cd-10 5.5hp how to tell if rings and pistons are bad?

Other than that, it sounds like a bad gauge. Try another, just for kicks.

Good point. My first gauge would only read 30psi. Got it from Harbor Freight. Save your money and get a better one from an automotive store.

Marv