Low compression after rebuild

[rdmcavo]

I did a rebuild on my 1986 marathon with the upper and lower rebuild kit from India. After about 1/2 tank of use with a 40:1 oil gas mix for break-in I'm measuring about 82 lbs. compression. I live at 6000 ft. altitude so I believe this is like 100 lbs at sea level. I would expect it to be at least 100 lbs at this altitude so I think the compression is low. The thing is, the cart runs great and starts great. Anybody have any Ideas?

Thanks Mc

 

[Nubs]

are ya checkin' it with the throttle all the way open?

 

[rdmcavo]

I did check it with throttle full open. I also went in to the catacombs and found my old compression gauge. I did a test with the old guage and got 105 lbs. Corrected for altitude that's about 125 - 130 lbs. I think this reading is more correct since the engine starts and runs so well.

Mc

 

[Nubs]

125/130 is about where it needs to be

 

[rdmcavo]

Thanks. I was worried about my rebuild. Now it looks like everything is OK with my cart.

Mc

 

[kogieblack]

When you say "throttle fully open", are you referring to pressing the accelerator pedal all the way down? I only get 110 psi but I simply "baby" the pedal enough to turn the engine.

 

[Nubs]

golf cart engines are setup so the starter engages before the throttle opens, with no idle circuit the butterfly is completely closed. if it can't get air it won't show a true number.