halatos2000

I have an RC10-GT with a .12CZ-Z motor I purchased back in 1995. It ran perfectly for the longest time, then I found that the dust cover on the end of the carb was cracked and hardened(2BK carb). The engine still ran fine prior to me taking the carb apart to replace the dust cover. I took the throttle lever off and replaced the dust boot, and it has not idled properly since. I took the carb back apart, put new o-rings on the mixture control valve and still have the same problem. I have completely disassembled and re-set the controls according to the manual and cannot seem to get it to run right.

I have sprayed carb cleaner near the base of the carb while running, and there is no change in the performance of the motor at a fast idle. The same holds true for the high speed needle. The throttle lever side of the carb is where I think the problem is, if I spray carb cleaner there the idle changes indicating an air leak, but I cannot figure out why it continues to act

The only way I can make the truck driveable is to bottom out the idle stop screw which opens the carb quite a bit. Playing with the mixture control screw will usually allow me to maintain an idle(albeit very fast). High speed performance is perfect, the exhaust trail looks normal and it is not overheating. I just can't slow it down without it dying out.

Anyone have any ideas?

Bax

My Feedback: (11)

If you have good fuel and a good glow plug, and the carb's adjusted correctly, then it's time to start considering that the piston/cylinder fit is starting to wear out. Poor idle and and then acceleration are the first signs that the fit is getting loose. It may be time to consider their replacement. Here's the stock number and retail price:

OSMG4815 21203010 CYL & PISTON 12CZ $44.99

These parts can be ordered through any hobby retailer who sells O.S. Max engines and accessories.