Jetting Help.

[Dobber]

Hey guys. I need some help. I've read all the jetting guides and everything and i cant seem to get my 450 jetted right. It has a full dasa exhaust and a custom made intake with no air box at all. Totally stock besides that. I've tried almost everything from a 155 to a 185 main.

It starts right up and idles great, and it seems to run very strong from idle to around 3/4 throttle, but when i hit WOT it falls right on its face for a couple seconds and then picks back up. It also wont pull to the rev limiter. Im thinking its rich, but 450s are totally new to me. Could it be a problem with the needle? Any help is great.

[eastside 400]

from your sig i am assuming its an 06? Try 175 main, 42-48 pilot, 45 leak jet, fuel screw 2.5 out

[DnB_racing]

also make sure that there isn't a dynojet needle, mixed with keihin jets. and use only original kiehin, a lot of the off brands can be off in the sizes, and make you think your trying a different size jet then you really are

is the feeling of it falling flat a bog, and sound bwhhhaa, or does it pop? if more of a bog then a popping then its sounds rich

if the bog is all the way from 3/4 to top its the main ,but if it just bogs then clears up then it might be the needle

check your needle and if its not adjustable then get a HRC needle or a NCVQ, if it is adjustable try moving the clip to around 3 from top and see if that helps

when coming back to idle, is it nice and smooth or does it hang or pop on decel?if so, its a good chance the a/f screw causing that

[Dobber]

its more of a bog i think. it almost feels like the engine is going to die. Its still the stock needle, and im thinking that might be the problem. Any opinions on that?

[quad2xtreme]

I'd highly recommend the HRC needle that was mentioned earlier.

[Dobber]

That's what I'm going to do. I've looked around for an hrc needle and can't seem to find a place to buy one. Can someone point me in the right direction?

[DnB_racing]

Originally posted by Dobber
That's what I'm going to do. I've looked around for an hrc needle and can't seem to find a place to buy one. Can someone point me in the right direction? I know these guys have both the hrc or the ncvq

you might have to call

http://www.xcbob.com/articles.html

[Ruf Racing]

Woodward Specialities (http://www.woodwardspecialties.com/)

[quad2xtreme]

Baldwin Motorsports