Why do you think its a problem? Does anything negative happen in the way it runs over a period of a tank full of run time? For whatever reason there seems to be a number of people running converted engines and they think they find wobbles or hear pings yet cant find complaint with the way it revs a prop. If the motor starts up and turns a prop with authority then try not to look too hard for problems that dont seem to effect the power the motor is already making. Piper