new wr400 owner needs help!

were is the air screw on the carberator and how do you ajust it to get the dead spot at the bottom end out. I've been riding for 30 years but never had a pumper carb it's totally diffent from ones i've worked on!!

thank's for the info , I ordered a # 45 pilot today I'll let you know what happens!

[This message has been edited by robman (edited 11-07-2000).]

Originally posted by robman:

were is the air screw on the carberator and how do you ajust it to get the dead spot at the bottom end out. I've been riding for 30 years but never had a pumper carb it's totally diffent from ones i've worked on!!

There is no air screw. Idle mix is adjusted via a fuel screw, the diff. is significant because, unlike other carbs, in is lean, out is rich because you are regulating fuel and not air.

The screw sits in a recessed hole in the fuel bowl. You can access it without removing or loosening the carb if you have a very short screwdriver. I use the bit end only (no handle) from one of those cheap combination screwdrivers. I marked it with nail polish so I could count the turns.

You may want to note the initial setting before you mess with is (although I think they are all set at 1.75 turns out). A quarter turn at a time is plenty, that is a lot of difference. You probably don’t want to go out past 2.5 turns, I think a few guys have had their fuel screw (or pilot screw) fall out.

Hope this helps!

Originally posted by Hick:

There is no air screw. Idle mix is adjusted via a fuel screw, the diff. is significant because, unlike other carbs, in is lean, out is rich because you are regulating fuel and not air.

The screw sits in a recessed hole in the fuel bowl. You can access it without removing or loosening the carb if you have a very short screwdriver. I use the bit end only (no handle) from one of those cheap combination screwdrivers. I marked it with nail polish so I could count the turns.

You may want to note the initial setting before you mess with is (although I think they are all set at 1.75 turns out). A quarter turn at a time is plenty, that is a lot of difference. You probably don’t want to go out past 2.5 turns, I think a few guys have had their fuel screw (or pilot screw) fall out.

Hope this helps!

I turned it out and messed withit awhile but it did not take the dead spot out ,what do you suggest?thank's for your help!

Robman,

If this is a US '00WR, then the dead spot is from the lean #42 pilot and lean straight diameter of the needle. (see manual in TUNING section)

Now if you have gone past 3 turns out on the pilot screw using the stock pilot jet, try the next bigger pilot jet #45 at 2 turns out(range = 1 1/2 to 2 1/2 turns). Next step is #48 at 1 turn(range = 3/4 to 1 1/2). Adjust the pilot screw as Hick described.

Also, if you want it better yet get the needle straight diameter in a smaller size with a DVP needle. (search Thumpertalk for the part number, 5BE-14916-DP, '99YZ option) This diameter is a good middle size to work with, and clip #5 works well with this needle.

Use the search tool for more, look for EKP.

James Dean

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