STUMPED 60 PSI of Compression After a Full Engine Rebuild

Asceder

New Member
2pg two stroke was running really slow and had 60 psi of compression, I did a full complete top end rebuild on the engine. New jug, piston, rings, head gasket etc, I am STILL only getting 60 psi of compression?????? It starts right up and runs but its very sluggish on hills! I have tried two different compression gauges, one is new, and the piston is in the right way. I also inspected and changed reed valve seals. I am stumped... Could I have a bad head? The vent tube also pours gas out of it, I am going to order a new carb today.
 

HotRodCarts

Cartaholic
Are you holding the throttle wide open when you're doing the compression test? If not try that it will make a big difference in compression. Welcome to Cartaholics Golf Cart Forum. :hattip:
 

HotRodCarts

Cartaholic
If the engine only has 60 lbs of compression there's a problem. Are you sure you installed the rings on the piston the right way? Or a ring possibly broke. I would say you'll need to take the engine apart again and check everything. @Nubs may have some ideas for you when he sees this thread.
 

Asceder

New Member
I just pulled the engine, the rings were upside down so i filled them over still no change. i installed the old head gasket and got 80psi gained 20 psi, so i am thinking it has to be in the head. I put a straight edge on it and everything looks straight. Is there anyway to do a leak down test?
 

HotRodCarts

Cartaholic
You can use a air compressor with the regulator turned down and pump air in the cylinder through the spark plug hole. I would say if the rings were upside down you need to re-hone the cylinder, replace the rings and use a new head gasket.
 

Asceder

New Member
Well good news i guess... I went to autozone to see if they had a leak down tester, they did not so i got a compression gauge just to see and the cylinder has 130 psi on it... What are the odds? my other two are broke ( one that is new) Note do not buy harbor freight compression gauges! I am going to reinstall and see if i can go from there...
 

HotRodCarts

Cartaholic
That's good news. You can use one of the other compression gauges to make an adapter to use for doing leak down tests. Take the gauge off of the hose and put a male air line fitting on it. Just make sure you turn the regulator down on the air compressor to about 10 PSI before doing the leak down test.
How's the golf cart running now?
 

Asceder

New Member
That's good news. You can use one of the other compression gauges to make an adapter to use for doing leak down tests. Take the gauge off of the hose and put a male air line fitting on it. Just make sure you turn the regulator down on the air compressor to about 10 PSI before doing the leak down test.
How's the golf cart running now?
The same... I shot a video and will upload it in a second. I also took the carb apart and checked it. I spayed starting fluid around the crank seals too see if there was any leak and it didn't rev up any.
 

Nubs

Cartaholic - V.I.P.
Did you try it with the muffler off? kind of sounds like the muffler is plugged up. fairly common with that style

ezgopluggedmuffler2.jpg
 

Asceder

New Member
Did you try it with the muffler off? kind of sounds like the muffler is plugged up. fairly common with that style

ezgopluggedmuffler2.jpg
yeah i cleaned the muffler and put too big if a tail pipe on it, i am going to change it back soon, its too loud for my liking.
 

NaturLblaq

New Member
Did yoy find out what was wrong? My rings are correct. The "R" is on the top side. It had 60 before and no change after rebuild. Did two rebuilds and still 60
 

NaturLblaq

New Member
I did. After reading a few post I decided to be patient, I put some oil in the cylinder, ran it for a while then revved if to a while. Ran it through a few cycles and it seems to be working. I guess the rings weren't seated. I stopped because I live in a neighborhood and I am tying to be a good neighbor. By the way I deleted the oil injection and ran 50:1. I can't figure out why my carb keeps overflowing. It is new and I don't seen any visual obstructions. Will try again tomorrow.
 

classycarts

Cartaholic
These days and with aftermarket parts, just because the carb is new, dose not mean it's good. I've had quite a few that I had to send back and get a replacement. All purchased from a reputable parts supplier.
 

NaturLblaq

New Member
That might be true but it worked fine until I started adjusting it. I am new to golf carts and initially it wasn't getting enough fuel. Turns out the hose from the crankcase was missing. Once I connected it it started getting fuel. While troubleshooting I removed the inline fuel filter because it was gross I bought another but I haven't replaced it. I am wondering if reinstalling the filter will restrict the fuel some preventing overflow m I'll try that next.
 

guitarman

Cartaholic - V.I.P.
If you leave the inline fuel filter off, there is a good chance that any dirt that is in the fuel tank will end up in the carburetor bowl and needle seat.
 
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