Main jets size

[fastbird]

I am in process of rebuilting carbs,and not sure what jets to use.
Bike does have supertrapp slip ons,and I live in Chicago not sure about altitude.Now I have 152.5 should I try 147?
Thanks

 

[one2dmax]

i'd go with the smaller 147.5's.

Sean

 

[fastbird]

Can i use 147.5 with k&n air filter?
Thank You

 

[one2dmax]

Yes, with drop in filter anyway.

Sean