updated photo of of my 83 marathon re-build

[mikeevans860]

so I got the top end put back together and the motor put back in the cart. Everything seems to work. the only problem is the compression is still coming back at 60...??? Thats what it was before the re-build. Now im frustrated......Please help.

[BrewCityMusic]

did you get the piston in the right way around? There's a thread floating around here with a video, the poor guy did his whole engine and had the piston reversed and had the same trouble, pulled it, spun the piston and all was well ...

(Feel free to jump in with that link, Dave)

[mikeevans860]

Originally Posted by BrewCityMusic

did you get the piston in the right way around? There's a thread floating around here with a video, the poor guy did his whole engine and had the piston reversed and had the same trouble, pulled it, spun the piston and all was well ...

(Feel free to jump in with that link, Dave)

I am pretty sure its right. the square hole in the piston should be facing away from the exhaust hole right?

[mikeevans860]

I am pretty dang sure that i put it in just like this one

[Dave Box]

Well the piston being the wrong way round will not halve the compression but it sounds like you have it right. To double check you can remove the exhaust pipe and look in the port. If you see the square hole in the piston as you rotate the engine then you are in a world of pain.

My first thought is that your compression tester is on the fritz. 60 psi twice? nah. Why don't you test the tester on another vehicle, if you get another 60 psi you need to get back to Autozone.

If the tester is OK then did you replace the cylinder as well as the piston, that is not clear from your thread (you say top end kit). If you have replaced the cylinder and the piston and the rings and you are really seeing 60 psi then you have a cracked or warped cylinder head. This can be the only place the compression is going and it is the only original piece on the top of the engine.

When everything else is ruled out, and hopefully someone with better ideas than mine will come along, you will need to pop the head off and as a crude test place a straight edge across the head and hold it up to the light. Can you see light between the rule and the head? To check for a crack you can turn the head upside down and level it with some blocks over clean newspaper. Now fill the head aperture to the brim with the thinnest oil you can find or kerosine. Leave overnight or 24 hours and see if there is oil on the paper or the level has gone down.

Let's hope that you have a defective tester that is maxing out at 60 psi

[mikeevans860]

Originally Posted by Dave Box

Well the piston being the wrong way round will not halve the compression but it sounds like you have it right. To double check you can remove the exhaust pipe and look in the port. If you see the square hole in the piston as you rotate the engine then you are in a world of pain.

My first thought is that your compression tester is on the fritz. 60 psi twice? nah. Why don't you test the tester on another vehicle, if you get another 60 psi you need to get back to Autozone.

If the tester is OK then did you replace the cylinder as well as the piston, that is not clear from your thread (you say top end kit). If you have replaced the cylinder and the piston and the rings and you are really seeing 60 psi then you have a cracked or warped cylinder head. This can be the only place the compression is going and it is the only original piece on the top of the engine.

When everything else is ruled out, and hopefully someone with better ideas than mine will come along, you will need to pop the head off and as a crude test place a straight edge across the head and hold it up to the light. Can you see light between the rule and the head? To check for a crack you can turn the head upside down and level it with some blocks over clean newspaper. Now fill the head aperture to the brim with the thinnest oil you can find or kerosine. Leave overnight or 24 hours and see if there is oil on the paper or the level has gone down.

Let's hope that you have a defective tester that is maxing out at 60 psi

I will check the tester when I get home. And yes I did replace the head and piston.

[mikeevans860]

I finally put a few more hours into this build. All the body panels are at paint right now and I am currently working on prepping the rest of the cart for a rattle can job. I pulled the motor back out and I still cant get the compression figured out. It is still around 60 lbs.???
I am going to take my other EZGO motor down and have a full re-build performed on it. That way I have 2 running motors even though one is kind of week.

[mikeevans860]

Here are a few more pictures of the motor all opened up

[mikeevans860]

and a few more

[doozerann]

Originally Posted by mikeevans860

just got all the body pieces off and now time to pull the motor. I just bought the top end re-build kit today for $180

Hey you should check out my 85, i have a 93 i'm working on now. loving it!!!!