I just installed this engine in a Tamiya TG10-MK2 kit. Now the engine starts fine on starter box but as soon as I put car on groung under load it stalls out. I've adjusted the idel screw with no success. Any ides on why this is happening. Thanks for any help.

sounds like you have some clutch issues. like maybe some shoes dragging at idle or a clutch bell bearing is seized. If its stalling after you start acellerating its probally a low end needle issue.

If I start it on the starter box and give it 1/4 throttle and put it down on grownd it will run but as soon as i slow down it will stall. also I'm not sure if this is supposed to happen but the car will not roll backwords unless the engine is started.

If you hold the car in your hands and then rev the engine what happens? Does it stall?

No it runs good and spinns the tires fine, It also ides ok but as soon as it tuches the ground it stalls.