I need suggestions on what jets to run with toomey pipes, boyessen rad valves, with no airbox lid on. I am already running 280s with the snorkel of the lid. I live 500 feet above sea level.

 

You didnt mention what air filter you were running. that makes a difference also. If your running 280's, you have already jetted for the pipes it sounds like. what do your plugs look like when you run it now??? Not only will the altitude make a difference, but the temperature outside will change your jetting also. cooler air is heavier, therefore requiring a larger main jet. Just a rough guess, I would thing a 310 to 320, not knowing what filter you are running. if your plugs are burning right, dont mess with it. its a good idea to have a variety of jets around though, incase you need to make a quick change. a properly jetted bike will run smoother and cooler for ya.

 

dune scooter was correct, i have my bike jetted for glamis which is about 500 ft. and i run 320's and it works good. i basically have the same mods as you, but i run duncan hi rev pipes, and i have a k&n filter w/ outware.