Hey if you have stock servos then I would replace them with something in the 150oz. torque range first. Stock servos will quite and leave you with a buggy heading out on a drive with out you, assuming you get it to start!

Sounds like a possiable air leak at the carb or backplate. Remove both and reseal them with a VERY small ammount of silicone RTV. Then after its back in the car, pull the plug and spin the engine to clear it out. Check the plug for glow and install it. Prime the engine with a little shot of fuel then put your glow on and spin it thru. If this doesn't work post again.

Let us know. BTW a tight gear mesh will not keep the engine from starting. The gears are not connected to the crankshaft. Its that little thing called a clutch that prevents that from happening. Thats why the car doesn't move when its at idle.

Good luck. Check out this 8th scale forum too.