Ok this sled just had the motor rebuilt , crank checked out fine. After the rebuild the sled would not run properly, TPS replaced and fuel rail. This helped but the motor still wanted to die out after being revved up seemed electrical.First run fouled first set of plugs in 5 minutes. Upon installing second set of plugs 8 miles or so down the trail blew the ceramic piece out of the plug??? After installing new plugs motor started right away. Another fifteen miles of sledding motor dies no spark. Where does a guy start crank sensor,ignition,stator coil etc.