Snorkeling issue for 05 brute

[mmud]

just added a 2" snorkel to my bike. At 2" for the air i'm running lean and I reduced at the end to 1'5" and to rich. Losing power at top and bottom. Anybody now exactly what i need to do for jetting?

 

[northern bear]

Buddy of mine snorkeled his 750 brute. went with 2 inch cause 1 1/2 was way to restrictive and couldn't tune it out. I'm thinkin he went with the 140/ 145 combo and shimmed up the needle with a couple thou spaces. left the air scew in stock position. but hes got a lot of other mods done as well and figures hes running about 75 horse with that machine