Would anyone happen to know why my secondary shift will not fully shift out on a 05 arctic cat 500
there is still about an inch down the belt where it can shift out and I’m only reaching about 60. Could it be where I placed the ear of the spring on the backside?

 

Not likely. The 2ndry helix ear location determines when it shifts, not how much it shifts. The ride height of the belt is determined by the primary set up.
The mudpro, especially the 500 is not a speed demon stock, it's designed for low end... not top end. When you say 60... are you talking miles per hour? or kilometers?

 

When was the last time you replaced your belt. or checked out the rollers in your primary, or the bushing in the movable half of primary.. These are just some of the failure issues i ran into on my 500 never had a issue with the secondary in 14000km. Loke alex said MPH or KM? I used to top out around 85km it may climb higher if i had a long strait stretch..