2007 yamaha 250 porting questions

[147motox]

i had my head ported and then i have a boyensen quickshot accelerator cover and a big gun exhaust. but it doesnt seem any faster than my 2006 with just the boyensen accelerator cover. what could be wrong with this? any help would be appreciated

 

[Ol'89r]

It would depend on who ported your head and if they knew what they were doing. The ports on most modern fourstrokes are very good from the factory. They only require a little clean-up to make them perfect. Extensive porting usually results in a loss of power.

Just my $ .02