2002 EZGO TXT golf cart will start and run briefly then cranks only. Robbins engine 295. Compression is 125 psi on both sides, carburetor and fuel pump new and clean and the spark is normal even as it shuts down. As soon as it quits running it makes a weird whistling sound that persists for a few minutes or until I open the oil cap and relieves the crankcase pressure or vacuum on the engine case. What might cause this issue?