Do I need a muffler?  By  Deleted (Read 1,971 times)

Yeah i have a nice thirty dollar spacer coming for it www.corsportusa.com/store/catalog/product_info.php?cPath=327_434&products_id=25755 I am going to run like that and dont think it will be a problem execpt for the loudness and it really aint that loud

www.aliexpress.com/item/Free-shipping-GY6-50cc-Scooter-Parts-Muffler-O-Ring-Exhaust-Gasket-for-GY6-50cc-139QMA-139QMB/732874648.html

Says exhaust o ring

a straight pipe actually does increase performance.
As long as the pipe's diameter is well calculated; (isn't too wide, nor too narrow).
Because of the pulses, a pipe behind the valves create a vacuum. That vacuum will suck exhaust gasses way better out of the cylinder than when pushing those gasses out into open air.

Most motorcycles and scooters have what's called a 'tuned exhaust'.
A pipe that will give best MPG in the RPM range it's used for.
Some sports cars, actually have a valve, that opens a secondary pipe, when the engine is revved high.

so instead of the exhaust gasses just exiting to normal atmosphere, they exit to a sub pressure, or somewhat vacuum, and they exit the engine faster, and more of the gasses exit the engine than in open air, resulting in less remnant burned gasses in the cylinder; giving better performance and better MPG.
Performance goes up in the likes of a few tenths to a few HP's depending on the size of the engine, and MPG can go up by as much as 10-20MPG.

Obviously the carb will need to be rejetted however in Florida it is technically illegal to modify an exhaust system unless you put another State DOT Approved replacement muffler in place. You may get away with mods to the exgaust unless someone complains about a nuisance so some does depend on the neighborhoods that you ride through along with the time of day.

Note that some backpressure is beneficial as it smooths idle and helps eliminate uneven pulses in intake manifold vacuume.