Seal? which side is up?

'03 S FCR from 99WR400(39mm) Yes I searched. Ran fine when parked. Only runs with choke now. Cleaned like 5 times w/carb cleaner. and replaced Seal on slide. Which side is up?

General simptoms are runs well on choke. fuel screw seems to have no affect. cleaned pilot jet. will not idle with choke off and pops on decel. seems lean. I likely just need to clean more,but wanted to check and see if this is common to a certain problem.


I would think that your '99 wr400 carb wouldn't be much different then the '02yz426 carb. I was just reviving my old bike and found the needle valve (some call it float needle) was seezed in its seat. It oxidized between the aluminum valve and the brass/copper seat, after soaking and gently pyring I could get it out. A little wd40 and emmory cloth polished it up nice and now it works perfect. I had the carb apart 4 times before I notice what it was :confused:

I'm no carb expert but doesn't the choke allow extra fuel in ? sounds like a jet is clogged or the fuel regulator ("needle valve") is stuck. With my carb you can access it by just removing the the bottom bowl and removeing the float, no need to remove any jets at all. Remove pivot pin if the float doesnt lift out easily and bring the needle valve with it the valve is stuck.

Sounds like the pilot jet is plugged. The opening is very small, so I would just buy a new one.

Be careful with carb cleaner. It can really mess up gaskets and other rubber items.

Just no fun removing an FCR from the DRZ. I can do it in about 10 min. now,after lots of practice. Gonna clean the snot out of it AGAIN later today. Still not sure if I have the vacuum plate seal in correctly. SUDCO's diagram is not clear,atleast to me

also,make sure the slide plate is square end down.

Just no fun removing an FCR from the DRZ. I can do it in about 10 min. now,after lots of practice. Gonna clean the snot out of it AGAIN later today. Still not sure if I have the vacuum plate seal in correctly. SUDCO's diagram is not clear,atleast to me

A few more times and you'll get it down to just a few minute job. It helps if the ambient temperature is fairly warm.

Thanks for the tread link. Good news is I put it together correctly bad news is it still doesn't idle.

What kind of carb cleaner have you been using? Any immersion chemical cleaner used?

Can you see thru the pilot jet? not the air bleeds, the fuel metering hole. Run a fine wire thru it (wire brush brissle) or replace it.

CRC spray type, no emersion. I wont be able to mes with it until Monday likely. I dont have access to new jets without waiting for days. I wonder if pipe cleaners are a good idea or am I just asking for more trouble?

I cleaned the jet above the fuel screw,the main jet,and the one near it. still no help,I may just have to put more time and effort into it.

Seal? which side is up?

for reference:



upside down:


and be sure that the seal isn't twisted:



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