1999 WR400F Help

[cmayer31 3]

All right, so my roommate picked this bike up a while ago and it's been nothing but a pain in the butt.

I ordered a JD jet kit, a zip ty fuel screw, and a new choke plunger to try and get the bike to start. When I went to pull the carb I noticed that the accelerator pump appears to do nothing...I think there's a linkage missing.

Is anyone familiar with the early kiehn carbs that might be able to tell something from the below pictures?

Here's a shot at the accelerator pump arm with the throttle fully closed:

And a shot with the throttle fully open:

Notice the black arm connected to the AP plunger doesn't move at all, but the silver arm from the throttle moves backwards away from the ear on the black arm.

No where in the throttle range does the AP plunger ever move..it should move at some point right?

Here's a picture of both sides of the carb if they make a difference:

The valves are within spec, the carb gets fuel, the choke is new, the hot start is fine, but yet this bike hates to start. I need to get it running to figure out the wiring to get lights working, and then eventually replace both leaky fork seals, and maybe even ride it.

[bikeslut 1]

did you find a microfiche to see if anything is missing? bikebandit sometimes has a very complete fiche

also; that allen screw that goes in to the black grovved thing... is that supposed to be tight, so when the arm moves, the plunger depresses, too? can you rotate the black piece without the silver arm moving?

but- that is not the big cold start issue, is it? it should start without that, unless I'm wrong... which... haha... really?

"burned" on thumpertalk is pretty helpful, as long as you ask with the right info to start with... including squirt time, current jetting, etc

http://www.bikebandit.com/houseofmotorcycl.../m8111sch113795

this might work

[cmayer31 3]

I've been using the microfiche from bike bandit, but the bracket doesn't seem the same, or the exploded view confuses me...probably the later.

I played with the spring and the allen bolt, thanks for pointing that out!, and I have the AP moving with the throttle now. Also replaced the AP diaphragm, spring, and o-rings. You're right about that not really affecting the cold start problem, but hopefully I can get it running to see if that makes a difference mid-high throttle.

I'm doing jetting now and will use the JD recommended 170 main, stock pilot, there's a 60 in it, so I hope it's stock, and blue needle with the clip in the third position.

It also had a horrible backfire, but I'm hoping fixing the rotted choke plunger and getting a good seat on the carb boots will make cure that.

[cmayer31 3]

Will it's alive!

170 main

48 pilot

68 starter

Blue JD needle

Clip in 3rd position

Seems to be starting first or second kick, but I can't really ride it around the neighborhood as it is crazy loud. It's always been loud, but I forgot just how loud...it makes the XR sound like a scooter.

Anyone know how to repack a Pro Circuit pipe?

lol, said to hell with the neighborhood and took it for a spin. This bike is a blast, but it has a wicked deceleration backfire to it. Maybe a loose fitting in the exhaust?

[kellymac530 0]

open the fuel screw a 1/4 turn and see if that helps the decel pop.

glad it worked out...my buddy has a wr400 and he had all kinds of issues with that carb as well. he bought a yz carb off egay for 50 bucks and it runs perfect now....not sure why the wr's often have so many issues with their carbs.

the early yami 400/426 is definately a bike that requires a precise starting process, then they start fine, but mess up the procedure and they seem hard starting...

[TrophyHunter 15]

Pro Circuit

TT

Moose

Re: Pro Circuit T4 Repack Ended up speaking to the Pro Circuit importer here in NZ and he guided me through it. Dismantles from the exhaust inlet end of the silencer. Take the outlet end cap off. Remove spark cone. Remove 3 allen screws from the inlet end. Now comes the tricky bit.... No end of clamping in vices and pulling will get the inlet end to slide out!! It is pressed and glued in with hi temp silicone .. and this is meant to be a serviceable item!!

......and brute force is the only answer!

This is how I did it. If (with the end cap off) you look inside the silencer you will see that there is a lip about half way along the length of the inner boor where the bore steps up from 1" to 2". I slid the handle of a club hammer up there and rested it on the lip and held it there. Then banged the business end of the club hammer on the ground hard whilt the handle still rested on the lip. About 10 real hard bangs like that and the inlet insert started to come out!! Not pretty but it worked and no damage to any parts!!

Now comes to the interesting bit. From the out side the packing looked in good condition. But as I took it off I noted 2 things. Firstly there was about 20 yards of it!! .. and secondly where it was up aganst the perforated core of the silencer it was crusty and burnt ... this in effect was blocking the holes of the perforation. Also in my opinion it was too tightly packed which is a common mistake with 2 stoke packing. If it is too tight it looses its sound deadening properties and is also more prone to getting a crust on it. Might be ok if you want to change yours after every race but not sensible otherwise!

I gave the perforated core a good wire brush and reassembles using only half the packing (which was like new).

End result the noise level is MUCH LESS .. I don't have a meter but is sounds half as loud. Still plenty loud enough and sounds great but now at what I'd call acceptable levels.