It appears you have a problem. I think you have the FR-32FX engine, and it seems to be discontinued. Parts may be available, but you will have to do some searching. Maybe try the hobby shop.

It also appears that your engine may be made in China, ...that, and from old pricing I'd say it is a low budget motor. There's a lot of engines available that should bolt right in. Wether you want another low-budget engine, or a high end one, there's lots to choose from.

Is this your engine?

http://www3.towerhobbies.com/cgi-bin...?&I=LXTDM6&P=7

Try browsing the Tower's site for engine choices. You can also post a question on "best engine for my TNX.

I would guess that a piston and sleeve for a budget engine can be around $60-$80 where the whole engine can be bought for around $125 to $150. A high end engine would be over $200.

I hear teh Picco 28 is the king of Monster Trucks these days. Here's a link:

http://www3.towerhobbies.com/cgi-bin...&I=LXMCA4&P=SM

Not bad at $199. I cna't guarentee everyting will fit. You need to check crankshaft end to make sure your clutch will fit and opposite end in case you have electric start backplate you want to swap for the pull-start. Somebody should know....Anybody?