my bike has a new sbp expnsn chmbr and top speed is lower than before

[brandenclrk]

i just put an sbp expansion chamber on my chinese engine because the original piece of junk exhaust broke around the welds. Now my top speed has dropped and its kinda sluggish in the top end. What can i do? Do i need to adjust the carb or change to a higher flow air filter or what?

 

[5-7HEAVEN]

Does your sparkplug look white? If so, I'm guessing you need to richen fuel mixture.