He changed his bike's pipe, changed its intake, bought all the jets that were available, and then diddled around with the carb and all his jets until the bike wouldn't idle and was a bear to start. He finally chucked the whole thing and bought a pre-jetted aftermarket carb from Jeff. Then again, Brad and I tuned Paul's bike at the Rubicon by removing the carb, leaning the main jet, leaning the pilot jet, lowering the needle valve, and bending the float tang up about 45 degrees. It ran great for the entire weekend. Paul has not ridden the bike near sea level yet.
Chains are easy.
If they jump the sprocket, they're too loose. Then again, it could have something to do with his bike lacking a chain guide. Of course anyone who has fallen on a tire iron or rim in the heat of tire-changing knows that a little lube on a tire bead can go a long way. People use different water and detergent mixes, Armor All, and such as lubricants. I have found that Fantastik cleaner works best, plus it leaves your hands smelling nice and lemony.