should i use a 155 or a 160 main jet?

[honda 400ex 69]

i have a pro circuit t-4 pipe and i am going to get a k and n air filter what size jet should i use 155 or 160 or even lower?

[Pappy]

try both....i run a 155 and it uns like a raped ape. just keep an eye on your plug.

[honda 400ex 69]

so with a 155 it runs strong what mods do u have

[Wheelie]

Try the 155.

Look at my sig for mods and jetting. I ride at 0-2000ft. and the jetting works perfect.