I have an Excel spreadsheet that when you put in the altitude, temperature and jet settings for a properly jetted bike, it predicts the proper jetting at all other temps and altitudes. It prints out a chart that you can tape in your manual or toolbox. No math involved, just read the jetting off a temp vs altitude chart. And its FREE, thanks for all the help you guys have given me. I would like input on how it works for you, especially for the pilot jetting. I want to refine it and I need data. Tell me what jetting works best for your bike at a given temp and altitude, and what modifications you have on your engine. Email me at firstname.lastname@example.org and I will send you a copy. If you want more details see "high altitude jetting for 250F" topic in the 250F section.