Nitro car help
 

Hey People

I have problems with my nitro car, and was hoping some of you could help?? Here goes.

I recently bought a Tamiya 1/10 scale car, with a FS12-SS single speed engine, it has a 4WD layout.
Recently I tried to convert it to rear wheel drive by taking the shaft which leads to the front wheels making them turn, resulting in only the rear wheels spinning, all was ready to go, started the car up and nothing, didnt even move, just revved on the spot as i went to accelerate.
Put the shaft back in to bring it back to 4WD, moved the a wheel and everything seemed to move ok and looked set to go as a 4WD again, all was ready to go, started the car up and idle was good, went to accelerate and the engine would cut out.

I have tried playing with fuel mixture and throttle but to no avail.

Can anyone shed some light on this for me please.