JUST PURCHASED A 91 HF CRX FOR 600 BUCKS. WHEN I GOT IT IT RAN LIKE **** THE CRANKCASE WAS OVERFILLED. GOT IT HOME DRAINED THE OIL REFILLED TO PROPER LEVEL CHANGED THE PLUGS STILL SPUTTERED AND SMOKED A LITTLE. HAVE TO REV REALLY HIGH TO GET IT TO GO THE KID I BOUGHT IT FROM SAID HE CHANGED THE BLOCK TO A CX BLOCK AND KEPT THE HF HEAD HE HACKED THE **** OUT OF THE FLOOR PANS TO PUT IN THESE KNOCK OFF RACING SEATS. NO BIG DEAL NOTHING A MIG AND SOME SHEET METAL CAN'T TAKE CARE OF. MY QUESTIONS ARE WHAT COULD BE CAUSING THE CAR TO BACKFIRE AND WHY DOES IT NOT WANT TO GO MY GUESSES ARE TIMING AND CAP ROTOR WIRES AND BAD CLUTCH. NEW TO THE IMPORT SCENE