My 2004 Yamaha Midnight Star has been to several mechanics. It starts and idles fine, you start down the highway and sometimes it will acted like it runs out of gas. pull the clutch and it idles? I have went 120 miles and then it does it and i have went 3 miles and it does it. Never at low speeds always 60 or 70 mph. Had the jets changed new fuel lines new accelerator pump. The 5th mechanic has it now and is lost????