This auction is for one aluminum airbox adapter plate used to convert an 06-09 CRF250R to accept a CR500 engine.  This is not an auction for the airbox, but just for the adapter plate. This plate is made of 1/8" thick 5052 aluminum.  It is cut out on a CNC water jet then de-burred in a media tumbler. It comes with all the holes pre-drilled and ready to assemble with your airbox. This is made to be use with an airboot from a 1998-1999 CR250.

Download the Conversion Manuals. These manuals included detailed instructions and photos on how to perform each of the modifications for great looking results.

We offer billet aluminum Y-pieces, engine mounts, coil mount bracket, exhaust and silencer mounts, airbox adapter plates and radiator outlet parts for various engine conversions. We also offer complete kits at a discount. 

Check out our store ConversionParts500 for all of these components to make your conversion easy. 

We will combine shipping if you purchase items together and notify us that you would like them combined.

We are happy to provide our contact info to anyone who purchases a part so they can contact us with questions about the conversion process.