you need to drop the main jet down to a 150 or 147.5 see if it doesn't get better.
take off the air box cover and see how it does..if you go to a 147.5 and it does better with the lid off you may have to go to a 145,just be real careful if you go down in elevation
on our trip to colorado i had to drop from the stock 152.5 down to a 140 and still had to take the lid off the air box at anything over 11000 ft.we stayed at 9000 and it ran fine there with the lid on.next year i will drop down to a 137.5,that should do the trick.
take off the air box cover and see how it does..if you go to a 147.5 and it does better with the lid off you may have to go to a 145,just be real careful if you go down in elevation
on our trip to colorado i had to drop from the stock 152.5 down to a 140 and still had to take the lid off the air box at anything over 11000 ft.we stayed at 9000 and it ran fine there with the lid on.next year i will drop down to a 137.5,that should do the trick.