well, after a dozen phone calls and emails to customer service at Massimo Motor Sports, someone finally called me back.. First he claims he never go my emails and messages , then said well its out of warranty, even tho its been overheating since the day I bought it new at Tractor Supply, and Tractor supply and Massimo have record of it, I was just out of luck.. They wont even give advice.. Great company eh? When I pressed him about all the 500 and 750 MSU s overheating, he admitted the Hisun motors are junk and they stopped using them 2 years ago.. his phone call was recorded ... So any of you with MSU 500 or 750s, be aware Massimo could care less how much they break down, THEY GOT YOUR MONEY.. so its now going to repair shop for its 5th time in just 300 miles on it