Here's some video of the bike running with the lakes pipe open and closed. The camera picked up more sound of the chain rattling around than the muffler. I took it for the first test run under it's own power, With the throttle held closed with a paper clip, no brakes, and direct drive. You can hold it back with your feet and the belt slips of course. I have to make some guards to hold the belt away from the pulley on the engine or it drags on the belt and wants to pull. I was reving it up yesterday and it back fired blowing flames out of both muffler tips. I'll have to get that on video on some time.