Honda ATC200s exhaust changes

[Jason]

Have a 1984 200s with jets and Uni-filter and want to modify the exhaust. Will you get a performance increase from ONLY changing muffler/silencer and using the stock header pipe???? Is it worth it??
Thanks

[MountainRider]

when modifying the exhaust, it's best and easier to change the head pipe and silencer out as a set. The aftermarket silencer inlet ports are larger diameter (to fit the larger diameter aftermarket head pipes) than the stock head pipe outlet.

Performance increase from exhaust upgrades on 4 strokers is typically minimal