I just bought my 96 GTS last weekend and this was my first real weekend to ride it well after it ran for a while and I let it idle down a weird banging sound came from the engine kinda like it was running rough is this normal and I just need to turn the idle up or is there something wrong like a loose motor mount the impeller does not have a mark on it and I know the owner so I know it was taken care of so does anyone have any suggestions?