I have a "99 ZL500EFI that when riding at constant speeds around 40mph, the engine quits. It will re-fire if I release the throttle and get back on it. Someone said may be Throttle Position Sensor. Also, this thing is a gas pig! Might get 80-85 miles to a tank. Are there performance chips out there that will lean out the mix? I'm assuming it is computer controlled as it is EFI. Any help is appreciated. Can I still get service on clutch recall?