if i remove my spark arrestor do i need to jet my 300ex?

 

only one way to find out, in my experience though I would say that the 300 is lean to begin with. Are you just going to gut it then put the end cap back on or just pull it out? If you are just going to remove the assembly, then it may be a good idea to go up a couple sizes on the main jet.

 

Anytime you alter the airflow, in or out, jetting is most likely required.