Poor acceleration under load

[Txt93]

I have a 93 EZ GO txt with the Robin 295. It is having trouble accelerating and going up even the slightest grade. If the rear wheels are off the ground, the engine will rev all the way up and both clutches will operate properly. Things I have done so far: replaced the drive and driven clutches, drive belt, carburetor, spark plugs, and swapped the fuel pump out to an electric pump. I checked that valves are adjusted to .004. Any help is greatly appreciated.

Runs great on jack stands. Barely moves on the ground

[Cartmaster]

First thing i would do is compression tests, both wet and dry and come back here with the figures. which carb did you purchase, OEM or chinese clone? If it is a chinese one, i would clean up and replace with the original OEM carb before going much further. Those cheap carbs can be a nightmare to get right.

As long as your new clutches are working correctly, then hopefully we can rule out those as the issue.

Also can you remove the valve cover and get a couple of pictures of the valve adjuster screws and lock nuts on the rockers. That will help enormously to diagnose your issue.

[sthreatt]

Originally Posted by Cartmaster

First thing i would do is compression tests, both wet and dry and come back here with the figures. which carb did you purchase, OEM or chinese clone?

I agree with compression and carb. Might be time for a ring job/rebuild .

[StoveBolt]

Originally Posted by Txt93

Runs great on jack stands. Barely moves on the ground

Long shot but... stripped brake hub?

[Cartmaster]

I thought about that but he said it drives but struggles. A stripped hub would not drive at all. Its possible it might be binding brakes though!

He also says the engine revs freely on Jack's, so I assume it does not when on the ground. A stripped hub would allow the engine to rev freely but no drive to the wheels surely.

[StoveBolt]

Originally Posted by Cartmaster

I thought about that but he said it drives but struggles. A stripped hub would not drive at all. Its possible it might be binding brakes though!

He also says the engine revs freely on Jack's, so I assume it does not when on the ground. A stripped hub would allow the engine to rev freely but no drive to the wheels surely.

[CP241]

Most of them I’ve seen rev and work with no load but fall on their face when trying to actually drive them are carb related. If I were a betting man I’d say original carb is either dirty or damaged and the cheap china carb didn’t help.

[Txt93]

Thanks for the suggestions. I admit that it was a cheap Chinese carb. I have ordered an OEM replacement. I will update after install. I should have known better.

[Txt93]

Finally got a chance to check compression. Looks like that’s my problem. It’s making 86psi on 1 and 91 on 2. I adjusted the valves out to .006, and got the same numbers. Guess it’s time for a rebuild or swap. Thanks again for the help.

[CP241]

Make sure you are holding the throttle all the way open with your hands when checking compression. Don’t rely on the pedal to open it all the way.

If it’s not all the way open it won’t suck in as much air. The less air it sucks in, the less there is to compress so the compression numbers will be low.

I’d also double check the gauge. I don’t know that 90psi compression is enough for these motors to run at all. Worth a second look anyway