[Gadget-Man]

I have a problem with (bog) on the low end, at higher altitudes. I added a K&N air filter, and took out one shim on the needle. It seemed to help, however I still have the problems with the low end over 7,000 feet. (When you say you cut the spring on the carb)Is that the large one in the barel? Will this help or do I need to re-jet the carb?

 

[toolman]

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.

 

[sparky]

Go down two main jet sizes and add a dial-a-jet...Ive used one for quite a while on mine and it works well.

I use it for drastic temp changes instead of altitude changes, but its the same principle....

Look here:

http://www.thunderproducts.com/dial_a_jet.htm