2000 EzGo TXT Gas

[trig123]

Or worn out ramp buttons which is common on these driven clutches. Still need to know correct compression reading because 90 psi just won't work.
Maybe the valves are leaking and never were seated good ?
This engine should have at least 150 psi to run correct. 170 is better.

[JPonLKN]

Unless there is a crack in either the head or case cylinder walls. Look very closely with flashlight and magnifying glass.

My guess is there is a problem with the way the compression test is being performed and compression isn't the issue. To make sure we are all on the same page, pull a spark plug and screw in the compression tester, remove the intake and filter housing, manually open the throttle on the side of the carb all the way open, make sure the choke plate and throttle plates are all the way open so you have full air on the intake side, step on the accelerator pedal to turn the engine until the gauge settles at it's highest point. If you are still 90 there, disconnect the muffler, and do it again. If still 90, then you have compression issue and the problem is in the engine.
I'm betting it is electrical or clutches as has been offered. With no load, cart up on jack stands, does the engine appear to rev up as it should, clutches both run from fully open to closed, and vice versa? Then, while driving, seams to bog down, like it is driving in high gear? That would be the driven clutch. If it revs up, but doesn't like to drive, maybe stripped hub, probably driver side.

If it doesn't want to rev or run properly in gear while up on jack stands, then it could be electrical. Do the check on the voltage regulator to make sure you aren't over charging the system...there are threads on the forum that explain how.
You also may not be able to get full electrical current through the wiring to the coil. While it may check out from a continuity stand point, a poor connection at some point may limit the electrical current that can pass through the connection point or switch. Check your throttle micro switch by bypassing it. There is a red and green wire in a grey insulation cover that run from the engine compartment under the cart. Put rear of cart on jack stands. With the key off, connect the red and green wires. This bypasses the microswitch. When you turn the key on, it will try to start and run without the pedal. You still need the accelerator pedal to actuate the throttle at the carb, but it will try to drive, so best to do it with the rear on jack stands. Does it run better? If that didn't solve it, you can test the key switch the same way by connecting the blue and green wires that run from the solenoid area under the frame to the key switch. If you connect them, you eliminate the key switch and the cart will operate on the pedal without the key switch. I do this at the solenoid end of the wires, not the key switch end. Those wires are in a sheath and sometimes get rubbed raw and short. This checks both the switch and the wiring. If neither of them eliminates the problem, go through each connection in detail, making sure all the wires and connectors are in good condition, grounds are clean and tight, etc. One small frayed wire into a connector can cause all kinds of havoc. If a wire got pinched or rubbed raw along the wire somewhere, could be getting a small short.
Next, did you replace the ignitor and/or coil with aftermarket parts? How bout the carb? Inadequate fuel flow through the carb would cause weak performance too.

[slonomo]

I agree the compression reading could be wrong. Did the same thing, chased a compression issue that wasn't even an issue. I actually have 3 bad compression testers in my possession, all bought on Amazon for $40 or so, all perfectly engineered pieces of Chinese crap. Bought one from Summit and it works fantastic, although it was $100. For diagnostic tools, you can't cheap out, learned my lesson. I would sort that out first and make sure the gauge is actually correct, as already suggested.

It sounds like you've checked all the basics. I agree with the others that "performance" can be affected by the clutches and belt.

I also had a performance issue on a TXT, turned out to be the carb, it was also a China special. Spent the bucks on an OEM carb and it ran fantastic right out of the box.

Fuel quality can have a ton to do with performance. Make sure you have super clean good new fuel in there. Older fuel can have water and can be less volatile than new gas.

Check all your hoses and vac lines.