Bills... Port timing? Intake and exhaust? What is that? Does it create more power? Better performance? Is this something I need to do? Question about the muffler. If I cant find one can I build one? Does it require a vent nipple like on glows? Do you chamber it to reduce the noise level? Is back pressure figured in? Thanks! Al Please forgive the missspell on the previous reply; {bubby} Buddy.