I live and ride at around 700' elevation, eastern PA.
Just got a 2003 TW that now has 600 miles on it. I want to do the larger main jet and needle shim thing but not sure where to start. 130 132.5 main jet ? .030 shim? What else should I do to check over the bike? Do the valves normally have to be adjusted at 600 Miles? What is a good source for jets?
No two engines are exactly the same. Your stock main jet is #125. Yamaha has #128 and #132 available. When I have access to real gasoline Tdub runs best with #128 and 2 washers under the needle. When only gasohol is available, Tdub runs best with #132 and 1 washer under the needle. In both cases the pilot screw is adjusted to eliminate off-idle throttle lag when the throttle is opened quickly and surge at steady cruise at 35mph. This can change by 3/8 turn depending on weather conditions. 400ft altitude.