myst38.. if your composite carb is working fine then no reason to switch it. The new aluminum body carb is just more consistent from engine to engine, but if your composite carb is tuning ok then you're fine. We had a few of the composite carbs that worked well.

dandrat.. sorry it took awhile to get this answered, but the new CRF 3 port sleeve will not work in the older engine, the top of the sleeve is taller and wider than the old one. On your engine repair, you actually need to talk to Horizon Hobby, as Kyosho America has nothing to do with Team Orion customer service any more. I would highly suggest talking to a customer service technician first before sending it in. Horizon's number is 1-800-338-4639.