I have a 2004 1M 800 159" and I rode it in the mountains once last year with the clutching set up right out of the book for the elevation and it was terrible. (It wouldn't back shift) I have since upgraded the secondary spring to a purple Erlandson. I also have a green sno pro spring I could run. I have bought a few helixes off ebay but I am unsure of what to try first. I have a straight 49, a 53, a 55 and a 57/50. Any suggestions would be appreciated.