'04 WR450 Carb is a little rough-Mod Suggestions Anyone?

5 replies to this topic
  • JohnnycatWR450F

Posted July 18, 2008 - 07:50 PM


So I am a total newbie. I have had my WR450 for about 4 months and ridden quite a bit. It came with a moose jet kit but the carb was really rough. Eddie AKA Burned recommended the trash for the kit which is where it lives now. Back with the stocker. It gave up a lot of power but it is a lot smoother but not perfect. I can stall it by opening the throttle up with one quick motion. Also, it bucks and coughs a little through all jetting circuits.

What is the best way to boost power and make it consistent without bucking. I have spent at least 60 hours messing with the carb and just want it fixed. I also just started a new job that is eating all my time.

Is there a great kit that will cure my woes? Is the QS2 the answer? Power Now? How about Tokyo Mods? I am not even sure what they are or what they do. All I know is that riding is about the funnest thing I can do with my cloths on and I would rather be riding a smooth, powerful, responsive bike than fixing one.

Your help is always appreciated!!!!!!:thumbsup: :thumbsup:

  • Ak Yammy

Posted July 19, 2008 - 12:09 PM


The guys on here convinced me to spring for the JD kit and it was worth every cent. My 03 ran like crap surging, backfiring ect. Put in the kit a few days ago along with a Zip Ty racing fuel screw and the bike now runs like a champ.

  • William1

Posted July 19, 2008 - 12:41 PM


How many hours on the bike? Could have a worn needle jet (emulsion tube).... worth trying if recommended settings are not working.

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  • JohnnycatWR450F

Posted July 19, 2008 - 03:18 PM


I am going to order the JD kit right away... It has been recommended by just about everyone that I talk to. I am also doing the gray wire mod tonight.

One of my major problems is stalling at low RPM. This is probably becuase I am still learning to negotiate the trails and at low speed it seems tough to keep the RPMs high enough. A buddy of mine recommends a heavier flywheel. Is that the only answer or will the needle, the throttle stop or the gray wire help me keep the thing running?:thumbsup:

  • William1

Posted July 19, 2008 - 03:25 PM


Can't go wrong with a JD jet kit. Get a Merge Racing fuel screw if you do not already have an extended one.
You might want to run a one tooth small counter shaft sprocket. That'll let you go slow, keep the rev's up and reduce the need for constant clutching. When your speeds increase, pop the stocker back on. OEM flywheel is reasonably heavy to begin with.

I think you will be shocked at the performance gain the throttle stop and gray wire do, but they will do little for you in the slow stuff.

  • JohnnycatWR450F

Posted July 20, 2008 - 03:51 PM


Thanks all for the input... I did the gray wire and that alone made a big difference. The surging and coughing seem to be gone completely. The guy that sold me the bike gave me a smaller front sprocket so I will get that on this week.

This week I am also going to try the JamesNow mod. It looks like TT is all for it.

Thanks again...


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