WR426F Carb Question

3 replies to this topic
  • QNCrazy

Posted May 05, 2016 - 07:05 AM


Hello everyone, new to the forum.  I am reviving my 2002 WR426F after many years of sitting.  I new right away that I should rebuild the carb as I was having problems with it before the bike went into indeterminate storage. So far, I have dismantled as much of the carb as possible without separating the middle portion.  Soaked everything for 24 hours and used a small nylon brush to scrub any remaining gunk off the gasket seats and blew compressed air through all the orifices.  The carb was pretty clean actually.  I think I drained it before I stored it. Anyway, I was looking at it this morning and I noticed I missed two jets, the two facing the intake.  The smaller one came out easy enough and is clear, but the larger one is really stuck and I can't get it out so much so that the brass started breaking apart. It appeared it was plugged as well.  I worked with it a little to remove some of the gunk, but I know it is still plugged.  I'm thinking if I cant get it out, I have two options: (1) leave it and ream out the jet with fishing line as suggested in other posts, or (2) carefully drill it out and replcae with new.  What are the Thumpers suggestions? 


Additionally, what are these jets for and where do they lead to?  I figured if I can find where they lead to, I can run the fishing line from the opposite end.


Once I complete the carb, my plan is to change all the fluids, spark plug, and possibly the cable.  I have read that I should place about a tablespoon of oil into the cylinder and kick it several times with the compression lever engaged to prime the cylinder.  A friend advised me to use Marvels instead of oil, what do you think?  I hope to have her running within a couple of weeks.


Where is the best place to get a full set of plastics?


Your help is appreciated.  This is a great sight and very helpful for the DIY'r.  I have alread brought life back to my wife's TTR230 thanks to the information here.

  • toten

Posted May 05, 2016 - 10:04 AM


If you end up needing a new carb, more modern FCRs are better. I believe 05+ YZ450F carbs are the best option. Hopefully you don't need that though. 


I know for YZ426s you can swap a newer subframe on fairly easily, and then use steel frame YZ450F tank/seat/plastics. Not sure if you can do the same with WRs. If you can I'd consider it, for the YZ it's supposed to drop a few pounds, I prefer the newer plastics, and they're a little easier to find. I'm not finding any complete kits for WR426s. 

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  • 450crazy

Posted May 09, 2016 - 01:37 PM


I did a 01 426 carb last year. Soaked it like you did but that didn't clean it up well enough. Took it to a wiesco shop and put it in their sonic parts cleaner for two days. Was pretty much spotless. Replaced the gaskets and pilot jet. Still running like new. The 426s are just about bulletproof if you change the oil.

  • underground-mpyre

Posted May 12, 2016 - 07:10 AM


If ever you need a better carb for the 426, use this as a guide.






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