WE PUT A GX390 IN ONE OF OUR KARTS.GOT IT HARDLY USED FOR 250.00
40 SERIES CLUTCHES.A LITTLE FASTER THAN THE 6.5 THAT WAS IN IT BUT NOT MUCH .ONLY MODS ARE A PIPE,JET AND AIR FILTER..BUT HAS A HELLUVA LOT MORE POWER AND TORQUE THEN THE 6.5..I'M SURE WE COULD GET ALOT MORE SPEED WITH BILLET PARTS AND NO GOVENER.BUT NOT IN THE BUDGET RIGHT NOW
PULLS MY BIG BUTT UP ANY OF THE HILLS AROUND HERE NO PROBLEM.