450r carb Please Help

[chevtuff454]

Hi, I was wondering if someone could explain to me the difference between brands of jets. I am in the process of putting a 2005 450r carb on my 416ex. My motor has 10.6 to 1 compression, a stage 2 hotcam, K&N filter, Sparks X6 exhaust. I took the 450r carb apart, and it has a 118 size jet in it now. (hex head) I heard there is two different kinds of jets, and they are sized differently. Please help with what jets and sizes i should use. (both main and pilot) Thanks to all that help.

[GPracer2500]

All Keihin brand "hex head" jets are the on the same scale. The ones that are different are Dynojet brand jets. The 118 probably seems awefully small--and it is. That's the stock jet for the 04/05 450r and it's tiny only because in showroom stock form the engine is very plugged up. An 04/05 450r with an HRC kit or basic intake and exhaust mods puts you in the 180+ range, if memory serves. I've not personally tuned an 04/05 450r carb on a 400ex but you'll likely need to be way up there too.

[chevtuff454]

Thanks for you help......is there anyone else that would be willing to share some info?

[ohsobad_chevy]

Like GP said......start out a little fat and fine tune it from there. Start with a 180 main, 50 pilot and go from there.