HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
Ben_212

2004 wr450f carb issues

7 posts in this topic

Please help just bought my first wr and having some real issues with the carb, it does idle but it's dog rough, all of a sudden the revs seem to go up a considerable amount on their own and then just drop again the main pilot screw was turned all the way in for some reason and when I tried to set it to around 1 1/2 it revved its knackers off, turned idle down and still had same problem of fluctuating revs PLEASE HELP!

Share this post


Link to post
Share on other sites

Follow your hot start cable into the top of the carb. It will have a little plastic nut on the end of the cable that holds it to the carb . Make sure that piece is not broken. If someone had changed jetting on your bike in the past, it's very possible that piece had broke when they twisted the carb to get at the float bowl.

Share this post


Link to post
Share on other sites

You pretty much need to start from scratch.

If you don't know what's in there, it's time to find out.

Time to clean, replace, and upgrade.

http://www.dirtrider.com/features/protips/141_0707_keihin_fcr_carb_rebuild/

Read the pinned posts regarding uncorking and jetting.

It's a pain, a real pain, but so worth it when it's done.

Share this post


Link to post
Share on other sites
Follow your hot start cable into the top of the carb. It will have a little plastic nut on the end of the cable that holds it to the carb . Make sure that piece is not broken. If someone had changed jetting on your bike in the past, it's very possible that piece had broke when they twisted the carb to get at the float bowl.

YES, make sure that little plastic thing isnt broken! Had that happen on my WR450. The bike ran super lean always popping and ran so hot. Also get an air fuel screw from works connection. Makes adjusting air fuel mixture super easy. Good luck.

Share this post


Link to post
Share on other sites

Please help just bought my first wr and having some real issues with the carb, it does idle but it's dog rough, all of a sudden the revs seem to go up a considerable amount on their own and then just drop again the main pilot screw was turned all the way in for some reason and when I tried to set it to around 1 1/2 it revved its knackers off, turned idle down and still had same problem of fluctuating revs PLEASE HELP!

So how did you do with it Ben?

Share this post


Link to post
Share on other sites

Got right onto it took carb off n stripped it right down 1. The nut that holds the hot start plunger in was threaded to buggery and 2. The plunger itself wasn't exactly in the best of nick so replaced both bits new plunger and nice machined nut, there was only a very small amount of shite in bottom so that got cleaned out and still waiting on mix screw as they sent me a clutch lever instead time will tell I suppose when put it back on bike n try it. Which me luck

Share this post


Link to post
Share on other sites

Got right onto it took carb off n stripped it right down 1. The nut that holds the hot start plunger in was threaded to buggery and 2. The plunger itself wasn't exactly in the best of nick so replaced both bits new plunger and nice machined nut, there was only a very small amount of shite in bottom so that got cleaned out and still waiting on mix screw as they sent me a clutch lever instead time will tell I suppose when put it back on bike n try it. Which me luck

good luck

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0