Saw this and like the look of the exhaust pipe and I'm using that same engine. http://www.ebay.com/itm/Motorized-G...944243ab44c31b1e3fe397&pid=100506&rk=1&rkt=1& Anyone using a long exhaust pipe like that one on the bike linked above. My main question is would that be louder then stock and would you gain or lose performance? I don't know with these small engines if you would have a problem with back pressure or anything like that? Seems that a long exhaust might be too long for the exhaust to proper flow out? Also that is just a straight pipe so I'm thinking it would most likely be louder then stock? Anyone using an exhaust on their 4 stroke that is quieter or adds performance? Doesn't seem to be many exhausts out there for a 4 stroke engine or at least that I can find? Going to build another bike but I'm upgrading everything form a basic bike to a mid range bike. Thought an exhaust pipe might be cool. Lawn mower looking exhaust on a Hausheng, not so cool.