i have a 675 and it ran great up to about 6000 miles then it dropped a valve, was in the shop for about 2 months getting rebuilt, put about 400 miles on it never revved it over 8000 rpms, and blew up again cruisin down 490. both times it blew up i was just cruisin down the high way the second time i was actually in traffic during rush hour in a construction zone and it was hot as hell couldnt get any worse