Compression Test

[Firebob]

Anyone out there know what the compression should be on a 88 2 stroke ez go. I just put a new piston, cylinder and crank seals in. The compression reading I am getting is 90PSI. It had only 60PSI before the rebuild. I was told it needed about 120PSI to run right. Just want to double check that number with the expertise out there.

Thank You
Bobby

[imnts2]

I sure am not a 2t expert but from my banging around a lota years, I like the 120 number. Is this a twin cylinder? If so, what is the other one? I assume you homed the cylinder prior to assmebly? If you did not, I sure would open it and do so. Cross hatch it enough to break the glase. and start it. A little runing should not hurt it and should result in a bit higher compression.

good luck
lefty2

[Firebob]

It was a brand new piston and brand new cylinder with new cross hatch. That is why I am concerned with the 90 psi reading. It is a single cylinder two stroke.

Thanks
Bobby

[Dave Box]

I have to tell you that 90 psi is low but I wave my magic wand and predict that your tester is shot. Seriously a new cylinder and piston will give you about 110 psi and as it beds in (and as you get a little carbon in there) the reading will increase to 140 psi.

Here is the best advice you will get. Does it feel good? Does it start? Does it get you 12 + mph on standard tires?

If so enjoy your cart and don't get hung up on the numbers.

Dave

[Firebob]

Hey thank you for the advice, although it starts well it does not run good at all. there is no way it it close to 12 mph and there is a lot of ( shuttering as I describe it ) it goes and shuts down it goes and shuts down. Sounds like a barrel valve on a alcohol dragster. Also not sure if the carb is adjusted right or the cables to the carb are all adjusted right ? I will try another compression tester but if you have any other advice let me know.

Thank You
Bobby

[Dave Box]

Bobby we have two problems. The first is that your cart just isn't right and the second is that I have just polished off a liter of Merlot. So unless anyone else intervenes I will be back tomorrow with some (hopefully) useful advice.

Dave

[Firebob]

Sounds great !!!!!!!!
Good Choice !!!

Thank You
Bobby

[Nate69]

Hey Firebob i had the same thing happen to me !!! And she runs wild to !!!! As my son would say she scary fast , lol. Dont get hung up on #s around here i was going to redue the hole engine again but i thought the heck with it ill run till she blows.

[Firebob]

I agree but when it still does not run right and has no power after doing a top end rebuild there has to be something else wrong. What frustrates me is that I can build a 10 second 1/4 mile race engine but a 2 stroke golf cart engine kicks me right in the butt. I seriously don't know where to turn to get this thing to run right.

Thanks
Bobby

[Dave Box]

If you have access to another tester I would retest the compression. If you still see 90 psi then you have an issue, possibly a warped or cracked head or maybe a defective gasket.

If, as I hope, the second tester gives you 100 + psi then we can look at the engine performance. The first red flag I see is the rebuild. You have the symptoms of the piston being in backwards so the first question is, were you aware that the ports in the skirt must face the carburetor? If you are sure it is in right then we can move on. If there is any doubt then pull the exhaust pipe off and with a flashlight look up in there whilst someone turns the engine by hand (taking the spark plug out first). If you see the ports you are going to have to pull it apart again.

If that is good then the symptoms you describe are identical to those I had when I kinked up the carburetor breather pipe. So if you have that pipe still fitted just pop it off to see if it is blocked. If you don't have the pipe just look at the vent on the top of the carburetor to see if there is any junk in there.

If the governor cable is fitted I would remove that just to make sure it is not the culprit, we can put it back and adjust it later.

If we still haven't fixed this then I would look at the inlet side. The 2PG is very intolerant of air leaks so did you use new gaskets on the inlet side? You can check for leaks by squirting some WD40 on the unions with the engine running. Any change of speed or tone indicate that you have found a leak.

Try this and let us know what transpires.

Dave