I HAVE A 1979 EVINRUDE 55 HP. (COMERCIAL?)??? ENGINE! I JUST BOUGHT IT FROM A SELLER THAT SAID IT RAN! OH WELL.... I GUESS IT'S BUYER BE WARE! ANWAY, THIS MOTOR WILL ONLY BACKFIRE. WHEN I TRY TO START IT?? I'VE CHANGED THE KEY, UNDER THE FLYWHEEL WITH NO AVAIL!! STILL BACKFIRES??? ALSO WOULD LIKE TO KNOW WHAT IS THE DIFF. BETWEEN A SO CALLED COMERICAL MOTOR & ONE THAT IS NOT COMERICAL???? IS ONE BETTER THAN ANOTHER??? OH YEA, WHAT DO YOU THINK COULD BE THE PROBLEM WITH BACKFIREING??? THANKS, VERRY MUCH!! AL.. SEMPER-FI......
