I keep having difficulties with my RD04. After running it for almost an hour or more, all of a sudden it stops as if no gas is reaching the carbs. Once i could fix it by opening the gas tank lid!!!??? Today that one didn't work. I noticed that the engine heats up when i am in slow traffic or moving slow it gets close to the red mark on thermometer (that was the case today too) . Any ideas? Known issues? Could it be the fuelpump? Why is there a fuelpump and when and how does it operate?