WR400's been sitting for a while...help

9 replies to this topic
  • rayroy1

Posted September 26, 2010 - 08:05 AM


Hey guys

I just got back into ridding and my 2000 WR400's been sitting for a while. I drained the tank/carb and put new gas in, changed the oil, and finally kicked it over w/choke on. The idle was exceptionally high with the choke on but after it was warm i took the choke off and it sputtered and died? This continued to happen which doesnt make sense b/c about a year ago it ran perfectly. Has anyone run in this or have any idea what to do? I really want to avoid taking it to a shop....

Thanks for all the help


  • William1

Posted September 26, 2010 - 08:13 AM


Replace the pilot jet.

  • rayroy1

Posted September 26, 2010 - 09:07 AM


with the same size? Do you think its plugged? could i just clean it or do you figure a new one is required?

  • 2FlatsandBent

Posted September 26, 2010 - 09:42 AM


If gas has been sitting in the carb for a while there’s a fairly good chance that there is some glazing or gelling, especially if you had bought the gas in the summer. Before buying any new parts try cleaning all the jets, passages and internal areas with carb cleaner. A good indicator of build up is if the float bowl looks yellowed or if there is any gunk in the “corners”. Also since you have the cab off inspect the boots to make sure there’re no cracks – look at these carefully; cracks are sometimes hard to see. Check your fuel line also and make sure it’s intact. Old fuel lines get hard and deteriorate. Also inspect all the vent/ overflow hosed. Once you have it all clean and are sure everything checks out then see how it runs. Check other posts on resetting your fuel screw.

The thing is, if you change your pilot and that works, chances are the old pilot was gunked up as suspected. However if the pilot is gunked up then the rest of the carb is also likely gunked up and you’ll then have a bike that idles but doesn’t run right in the rest of the throttle range. Sometimes carb cleaner doesn’t get all of the gunk and you’ll need new jets anyway; if so you may as well get them all. Just try cleaning first. Remember, clean is king – always…well, except for the actual riding part – and mud wrestling.

  • William1

Posted September 26, 2010 - 02:15 PM


I never try to clean the pilot, the orifices are too small, even the least amount of a film makes a difference. And yes, the same size.
When you remove the cap on the bottom, if it is spunky, you will want to pull the carb and clean it, if it is clean, then just the pilot is what you need.
For the $5 a pilot costs, cleaning is not worth it. Once removed, you can dunk your old jet in some super solvent for a year and hope it comes out surgically clean and try it the next time it happens

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  • rayroy1

Posted September 26, 2010 - 02:59 PM


sweet thanks alot guys ill give that a shot and get back to you with the results

  • 2FlatsandBent

Posted September 27, 2010 - 06:49 AM


Note the 3rd to the last sentence of my previous post.

The bottom line is that if the pilot is gunked up then more than likely the rest of the jets are also [and they are all too small]. You can clean the pilot enough most of the time to see if that may be the problem and you don’t have to drive out the a shop or wait for a part to come in. I just did everything suggested in my previous post for a 426 that had been sitting for over a year. While you’re right there at the disassembled bike, clean it up, check everything, see if it runs. After checking everything you can then go to the shop and get everything you need at once, i.e. new jets, boots, fuel line or what ever – easy.

  • 2FlatsandBent

Posted September 27, 2010 - 07:22 AM


BTW – I don’t mean to pit an argument. William1 has way more experience than I do. I’m just looking at it from the perspective of being at home in the garage, not having parts lying around, and not living that close to a shop. Some of us have inconvenience and time to overcome, not just cash – however little a part may cost.

Sorry for the boomerang. Good luck with it.:smirk:

  • rayroy1

Posted September 27, 2010 - 02:32 PM


Thanks for the input guys
This will be my first time tearing the carb apart so im a bit nervous but hopefully a good cleaning/once over will reveal the culprit. I have a shop manual and a bit of experiance so hopefully all goes well. wish me luck.........

  • 2FlatsandBent

Posted September 27, 2010 - 04:00 PM


You got it.
I would suggest stuffing a clean paper towel in the intake once you get the carb off to keep anything from getting in there [bugs love all open holes on motorcycles]. Other than that just make sure you work in a nice clean area and keep everything sparkling when you put it all back together.
Oh yea; careful twisting the throttle assembly once the carbs off. It’ll shoot a good squirt out even after you’ve emptied the bowl. Point it to some pavement or into a jar or something. Watch your eyes:cry:. Most manuals don’t mention this. I’m just sayin. :smirk:


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