In most setups an FM radio system will work. However since you are using a gas powered motor (chain saw motor) this might create more RF interference or noise that can affect the operation of the radio and receiver. If you do have these problems, the information that schmelme wrote in his post would help to resolve these issues.

For FM radios you have the choice of the Aggressor FM, SRX, or the CRX. Any of these will work for your application.