I have an HPI car with a 012 engine, it is an older car and i have finally got it to run for a short period of time ( i bought it used and the former owner has passed away and i can't get any information about what he has done to it) the guy at the hobby shop says that he thinks the piston sleeve may be in wrong, so after disassembly the sleeve appears to be in correctly all the ports line up. It will run as long as you give it some throttle but as soon as it goes back to idle it shuts down. Any ideas?