New to Site - '06 WR450 Rough Idle & Bogging at Take-Off

Hey guys - I am new to the site, but have been following for a long time. I have a 2006 WR450 that I recently picked up here in Colorado. It only has a few hundred miles on it and has sat most of its life. I got it home and immediately knew the carb needed cleaned as it would not idle. I completely cleaned the carb and it now runs like a champ at mid to full throttle, but idles rather rough yet and bogs when first starting at lower RPM's. I am hoping the experts on here can point me in the right direction.

More Info on setup:

  • Air-Box Mod
  • AIS still on bike (put it back on test idle)
  • Cleaned Carb completely and all jets are open/clear
  • New Gas

I have been working on and riding bikes for a long time, but for some reason this one has me stumped. I have been a Honda guy previously, so I am not that certain about the WR's. I am at 6000' in elevation.

Any help is appreciated - Matt

I was in the same situation a few weeks ago, having picked up a barely ridden 06 with similar issues. I would encourage you to read through the stickys at the top of the forum page :thumbsup: , there is an overwelming amount of info in there. Specifically the stuff on AP timimg/mods (accelerator pump) and leak jets. My bike is a whole different animal now. Good luck. :thumbsup:

We all have been there. I have an 05 (same bike) and experienced the same problems.

You can do the following to quickly solve your problems.

1. get the JD Jetting kit, install it according to the instructions. Follow it exactly. Your jetting will be very good.

2. adjust your ap squirt timing.

3 get an adjustable leak jet for to fix the bog or... you can just buy a larger leak jet and adjust the squirt duration. The adjustable leak jet is easy, but going up one size on the leak jet is much, much cheaper and just as easy to do.

then go out and ride and enjoy.

Inspect the passage above the pilot jet, if you are unable to get the bike to run at at idle.

Thanks for the information guys - after reading a lot last night on here, these are good thoughts. I am planning on pulling the carb back off this weekend and re-jetting to make sure it is good to go. I just ordered the AIS removal kit, so I noticed that comes with a new needle and a jet or two. Is the JD Jetting Kit a must, or can I just purchase jets as needed to tune properly? I see that it comes with some other items for the Accelerator Pump too. Thoughts? I am all for supporting a business on here.

Also, for the AP - what is the best way to adjust? I didnt think that was easy, but I could be wrong. If there is a link to a topic on here that shows it, i must have missed it. Since the bike sat a while, could the rubber pieces of the pump be bad possibly?

I hear a lot about this JD Jetting screw - is that a must to get too?

I will plan on re-checking the passages above the leak jet again and see what I can find.

Thanks for the help - Matt

JD Jetting has special needles it creates. You can't buy them anywhere except as part of the kit. All needles are not created equal.

they have everything you need right here.

I prefer the spring to the oring. The oring will break eventually and you'll have to replace it over and over again.

Simple stuff to do.

Well I'm going to recommend not going with the JD kit as it seems way overpriced and doesnt come with leak jets or an AP spring etc..

I purchased all my jets through Yamaha (always use OE keihin jets not aftermarket anyways) and simply bought a NCVQ and a NFLR needle jets these are aviable through Yamaha and seem to be the most popular for people using OE needles. Avoid brass needles as they wear quickly and can even wear the jet needle. Yamaha OE was way cheaper than anyone else to boot,10 bucks a piece for needles!

I purchased a KTM acc pump spring as its 5.00 compared to 16.00 for other heavy duty springs and also got there air screw as its stainless and has a o-ring to keep dirt out of the threads and help stop movement due to vibration (not 5.00 bucks).

toyko mods and jetsrus also had a good selection but were a little more expensive and cant offer OE needles (but did have the washer and gasket for the air screw as KTM doesnt send them with new one).

Saved a lot of cash and got more goodies, thats what its all about right? I'm happy to share where I found all my stuff at along with part numbers etc..

Now let the flogging begin for not going with JD jets.

It's not about the jets when going with JD.

It's about the instructions, the tuning options, the ability to have all the jets delivered to you at once, and most importantly, the quality stainless special-tapered needles. Add a leak jet and a merge racing apump linkage spring and you are golden.

Some of us don't have the time to go digging around for days just to save a few bucks.

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