I just bought a new 06 450r. i was wondering what to do now. i have a full dmc afterburner exhaust, k & n filter, and that's it. the directions told me to put the needle at the 4th position, did that. then start with a 128 main jet. did that, still way to lean, now i'm up to a 136 or 138, there is only one bigger jet size left in the kit, and i think that is an 140. what would you guys suggest i do next. oh yeah and the air/fuel screw is turned out 2.5 times like the directions recommended. want to go riding this sunday, thanks for the help in advance. the spark plug ceramic is starting to turn a pinkish color, and i run 93 octane.

 

Do you have a vented air box or running no airbox lid? If so you'd be around a 180 If you lid is on and your only mod is a pipe you should be 120 to 130(max)

This is for an 04 to 05,Not sure if the same hols true for the 06

 

The '06 has a totally different carb so 04/05 specs won't help. Good question though, do you still have your airbox lid on?

 

Sorry, yes i am still running with the air box lid on. i ride in very dusty and sandy condition's.

 

Not sure if the Dynojet sizing is the same as the Honda jets. I know for the 400ex they aren't. Dynojet does their own thing so watch when you are given advice. You aren't going to get much gains if you don't open the airbox up. The K&N won't flow any better than the stock filter. Most people riding in the dust prefer a foam filter too.

/Jon

 

Is your quad running better or worse as you have been jetting it up?

 

The quad runs great. it doesn't backfire or anything when i let of the gas, and the power is right there. I checked the plug last night, it's not near as white as it was. I checked the top end this time, by goin full speed full throttle and then killing the motor. the plug looks decient, it's not near as white, and is a real lite tanish color, personaly i would like to have it a little bit darker. how much gain would i get with the air box lid off? and what would that do to the jetting i have now.? thanks again for the help.

 

I would keep jetting up if you are unfamiliar with this quad, because you may been still running a little lean. Keep jetting up a size and see if your performance improves more and just back down to the jet that seemed to work best. I would leave the lid on if you want to keep the dirt out of your motor. If you take it off you will have to jet up alot more likely.