I have a zenoah 230PUM that I would like to modify to a 26cc pum. I know it can be done with the 231pum but I am not shure if this would work on the 230 (older motor) If any one has done it could you let me know?

It's great that you want to modify what you have to make it better. But the 4 port case ( 231/260 ), is available from Carlo ( CC Racing ) for $25. That assures you that both sides of the transfers are perfectly matched/balanced to each other at the factory. Then when you get tired of the stock 260 performance, you can do all your grinding on the 260 jug to up the game. I just wouldn't spend any time on a 2 port case. But if it makes you happy to try it, have a go. All the best with the eng. either way.

The problem is the G23 cylinder bolt pattern doesn't match the 231/260 pattern. However, before there was a 231 or 260 there was the hybrid. The RC car two bolt, 4 transfer cylinders could be modified to fit the G23 case by slightly enlarging the holes and grinding the old crankcase to line up with the transfer opening. The fins were turned off the cylinder to fit a standard cooling jacket.

The suggestion of a new crankcase to fit the 260 cylinder is a better solution, though. Unless your g23 is new, buying a new 260 with all new parts is an even better idea.

Lohring Miller

Thank you both for your advice, I think for as long as it work I will keep the motor as is & change to a 26cc when it pack up!
Cheers