Need Suggestions on Carb Issue

[KitV]

Well, several years ago I ran the bike at sea level with a #210 main jet & a #40 pilot jet. This was the carb tuning when I lived in Bend, OR (elevation 3,600 feet). The engine seized within a mile. I don't know if the #220 main that I am running now will also be too lean.

[matt glascock]

From 3,600' to 0' altitude is an >2X larger altitude drop that your upcoming trip so that's likely behind the lean condition seizure going from Bend to sea level. With your past seizure issues, I can understand the justifiable hesitancy to run the risk of a lean condition seizure again. Take a few sequentially larger main jets, a handful of properly gapped spark plugs and a couple extra JN e-clips (easy to lose) and you should be set for any eventuality. A couple jetting runs at sea level should sort it all out.

[Bullfrog]

Slap a 240 or 250 in 'er and see if she'll run at WOT. (The main jet controls mixture at full throttle.) Its an easy check to make. I think you are still gun-shy because I failed to identify that you had a 5D5 needle when you experienced the sea level (and other) seizures. You've got a 5EJ13 or 5F21 now right? When tuning the carb ranges (let's say by 1/4 turns of throttle settings) - go to the book and be deliberate about the jetting procedures