I sure hope there are some motorcycle gurus on here. On a whim, I bought a 1977 Suzuki GS400 at an auction. Paid $300. It runs like a bat out of you know where, except when it doesn't. It just cuts off sometimes. Any suggestions? We have emptied the old fuel, cleaned the gas tank, replaced the fuel filter, checked the hoses. Also, need new mufflers. The old owners manual suggests a two into one Hooker Header muffler, but I can't locate that online, and don't even know if it is being produced any more. Any assistance would be appreciated. THANKS! Rose P.S. Don't breathe a word of any of this to my son, who doesn't know I bought a motorcycle.