Engine can't move forward, but can backward

[Lavastar889]

Sorry for the paragraphs, but the issue summed up is:

The engine doesn't move the go kart forward, but does move it backward.



Specific model of go kart:

dong fang DF200gka



And here's the full story:

We got this go kart for free from this guy, he left it outside for a few years. Before than he said it was running fine until one day it wouldn't start. We got it, replaced the fuel line and filter, ingition switch, tires, and the battery. We cleaned out the carb and it starts and runs with starter fluid but doesn't start by itself. So we got a new carb that looks the same and is the same size, fits in the engine, etc. It starts right up now, however the engine bogs down when you go full throttle. We thought it was because the new carb has incorrect jet sizes, so we put the old carb back in, and it no longer bogs when full throttled(still needs starter fluid though). But, with both carbs, it has a strange problem: It doesn't move forward when throttle is applied, however, it moves backward in reverse(but it takes the engine to get to like 1/3 throttle to start moving). The engine isn't seized up and it's not the brakes/parking brake(it can be pushed either way easily). So I would appreciate any insight into why the engine isn't moving forward. And it's important to note: when placed into drive the go kart lurches forward a bit, and before it stopped moving forward at all, it would would at very slow speeds forward even when full throttled, then it stopped doing that all together.

 

[Lavastar889]

We think it's the clutch that's the problem, when you go into neutral it just preserves the last gear you were in.

 

[Karttekk]

Put the rear of the kart on jackstands then try turning the rear wheels manually. See if the engine will rev up that way. Maybe disconnect the chain, try different shifter positions. It's always safer to diagnose drive problems with the drive wheels off the ground in case the machine decides to launch on you. You could have a seized brake caliper.

 

[ezcome-ezgo]

Maybe I am reading this wrong or need more coffee. You start the engine up by some innovation and it runs ok. But the wheels turn in the wrong direction? Fantastic.

 

[Karttekk]

Disconnect the shifter cables and try shifting it manually. A shift cable could be seized up. You're saying the engine will rev up fine with the trans in neutral but the kart won't move in F or Drive? Glazed dive belt. glazed clutch friction surface, bent shift lever.

 

[Lavastar889]

Disconnect the shifter cables and try shifting it manually. A shift cable could be seized up. You're saying the engine will rev up fine with the trans in neutral but the kart won't move in F or Drive? Glazed dive belt. glazed clutch friction surface, bent shift lever.

I followed the cable, it seems to at least be moving the part connected to the engine

 

[Lavastar889]

Maybe I am reading this wrong or need more coffee. You start the engine up by some innovation and it runs ok. But the wheels turn in the wrong direction? Fantastic.

Sorry for the miscommunication, but when I say "runs ok" I simply mean stays idle and revs up. Not that it runs as in drives normally.

 

[TheShaww]

Sorry for the miscommunication, but when I say "runs ok" I simply mean stays idle and revs up. Not that it runs as in drives normally.

I have the same problem. Did you figure it out? It's like the clutch is full of mud when you try to drive forward, but drives fine in reverse. I see lots of people across the internet with the exact same issue, but nobody ever follows up with the resolution.

 

[Edwin Spangler]

I have the same problem. Did you figure it out? It's like the clutch is full of mud when you try to drive forward, but drives fine in reverse. I see lots of people across the internet with the exact same issue, but nobody ever follows up with the resolution.

Does the engine rev up without the kart moving as it should?

 

[Denny]

Transmission broken?

 

[Hellion]

Transmission broken?

You’d think.

The OP in the orig post made a roundabout ramble about the engine itself and not the transmission. Of course you want the engine in running condition to be able to move the buggy in either direction, but it’s the transmission.

Unfortunately it might involve some major exploratory surgery to solve the problem but I get it, no one wants to do the necessary because if it’s not simple, it’s not worth doing. The buggy engine does not look easy to remove or service beyond changing fluids… and even an oil change might be a hassle.

Is there a service manual for the GY6 engine out there in cyberspace ?

 

[TheShaww]

Does the engine rev up without the kart moving as it should?

Yes in neutral it sounds like a monster. Put in forward and it gets quiet like it's frozen up. Pushing the gas just makes it bog and act like the engine is frozen up. Reverse it works fine.

 

[Scout]

Sounds like a busted transmission to me.