build a 400ex

[Reggie44]

I've got a 400 with white bros pipe and k&n. I've got engine problems so I'm gonna open it up anyway. What mods can I add and still run pump gas. cam, piston, 416???? Whats your thoughts

[06_hondatrx_400]

Most big bore kits depending on the compression, it is recommended to run 94 or higher octain. But the more compression you have the higher the octain you will have to run. If u plan on putting a hot cam in you can just run pump gas.