[gdeanw]

I just installed the JD Jetting kit into my 2005 CRF 450x. I ride from 3000 - 9000 ft and jetted it for the 3000 - 6000 setting recommended by JD. However, it bogs from 3/4 to full throttle. I've tried every main jet in the kit with the same results. I have the Bomb head pipe and the quick shot accelerator pump cover installed. I've also removed the smog. Any suggestions?

[JAWS]

Which needle and what clip position? Was it from the top down? Did you take the slide out?
Joe

[[email protected]]

gdeanw,
We've seen this before,and each and every time it's one thing,and one thing only :
You're hitting the rev limiter.
With the stock jetting and airbox when the bike is moving, under load, the bike won't hit the rev limiter unless maybe you're rolling down a very steep hill in first gear with the clutch all the way out.
Now with the airbox open,a good exhaust and jetting, it will easily.
Most guys out there riding where you are riding that have a good exhaust system along with the aforementioned jetting and airbox mods run a 170 main.
If this is happening just before you're ready to shift, and of course that means you're really winding it out, then do the pink wire modification. Among a couple other things it'll increase the rpm the rev limiter kicks in by 500rpm, maybe just enough for you.
Know also that peak hp and torque are reached a couple thousand rpm below where the rev limiter kicks in, so if you're shifting anything much past 8500 rpm you're getting more noise only.
The way you have it set-up that'll be one good running 450X.
What Joe said is important too,and it's the only other possibility. The plate on the face of the slide looks like it does in correctly when in fact it's upside down, check out an exploded view of the carb on a parts fiche to see what we mean, because that will cause all kinds of whacky symptoms.
The problem is one of the two. If you've never removed the slide (and nobody else has either), then it's the rev limiter. Doug

[450xdirt]

Which needle and what clip position? Was it from the top down? Did you take the slide out?
Joe

I don't have this problem yet but I'm about to rejet my bike and don't want it. What and where is the slide?

[lightflight]

Which needle and what clip position? Was it from the top down? Did you take the slide out?
Joe

I don't have this problem yet but I'm about to rejet my bike and don't want it. What and where is the slide?

you dont need to take the slide out

[gdeanw]

Which needle and what clip position? Was it from the top down? Did you take the slide out?
Joe

I used the red tipped needle jet in the default position; I believe it was position #4. I did not remove the slide, I don't think.

[gdeanw]

gdeanw,
We've seen this before,and each and every time it's one thing,and one thing only :
You're hitting the rev limiter.
With the stock jetting and airbox when the bike is moving, under load, the bike won't hit the rev limiter unless maybe you're rolling down a very steep hill in first gear with the clutch all the way out.
Now with the airbox open,a good exhaust and jetting, it will easily.
Most guys out there riding where you are riding that have a good exhaust system along with the aforementioned jetting and airbox mods run a 170 main.
If this is happening just before you're ready to shift, and of course that means you're really winding it out, then do the pink wire modification. Among a couple other things it'll increase the rpm the rev limiter kicks in by 500rpm, maybe just enough for you.
Know also that peak hp and torque are reached a couple thousand rpm below where the rev limiter kicks in, so if you're shifting anything much past 8500 rpm you're getting more noise only.
The way you have it set-up that'll be one good running 450X.
What Joe said is important too,and it's the only other possibility. The plate on the face of the slide looks like it does in correctly when in fact it's upside down, check out an exploded view of the carb on a parts fiche to see what we mean, because that will cause all kinds of whacky symptoms.
The problem is one of the two. If you've never removed the slide (and nobody else has either), then it's the rev limiter. Doug

So, what is the pink wire mod? Do you have instructions or know where I can find them? Also, the bog happens on the stand too. Does that make any difference? Thanks, Dean

[belltownjefe]

See link below for Air Box Mod and Pink Wire Mod.

http://www.crf450x.net/2007/02/14/honda ... fications/

[[email protected]]

Good link to help Dean out belltownjeffe, it's a very easy job.
On the stand Dean, that doesn't matter either. The motor will easily hit the rev limiter now.
I didn't notice whether you did it or not but if you didn't do the airbox mod the engine wil be gasping for air at higher rpms, it's mandatory to either do it like the link
and the instructions for the JD kit show, or open the entire top of the box cutting along the molded in lines Honda provided to show you where to cut it.
Either way works, at least one of them is required,neither affects negatively your ability to cross streams, etc. The airbox is restricted so the bike will even run on it's lousy stock jetting, not because it's "protecting' the air intake. That job falls on a properly mounted,cleaned and oiled air filter. Doug

[gdeanw]

Thanks to everyone who wrote in! Everythings seems to be working well. I'll have my first ride in about a week to verify, but so far it looks and sounds great.
Thanks again!
Dean