installing jet needle

I just bought Baja Designs WR400 cam mod jet kit.Question is,how do you install jet needle and pilot jet?I've never had carb off of bike before.By the way,excellent forum.Wish i found it sooner.

Thanks Steve. Tell all your WR friends about this site. Your dealer too if he'll listen.

I just bought the Baja Designs jetting/YZ kit and installed it. YOU'RE GOING TO FREAK'N LOVE IT! :)

The needle is accessible through the top of the carb. You don't need to remove the carb to get to it.

I loosen the front and back clamps that hold the carb secure so it can rotate, remove the gas tank hose, remove the throttle cable cover and throttle cables (easy to adjust throttle cable once you've done it), and rotate the carb as best you can so you can get to the top. To do so you also have to remove one more hose attached to the carb. When you take the cover off, you need an allen wrench to undo the needle holder. At this point, the needle slides up and out.

It is tight but not too awful bad.

Note: You might want to change the needle clip position from 3 (stock WR) to 4 if that's what Baja Designs recommends.

Now, getting to the pilot jet is a little more difficult. But, not a lot more difficult.

It is located at the bottom of the carb. So, you have to figure out what else you need to remove to get the carb to rotate the opposite direction. I think I had to remove the float bowl drain plug (I'm used to that since I rejet often here in Colorado), and maybe one more hose.

You must then remove the float bowl and then this little plastic retainer inside the bowl. Try and remember how the retainer comes off although it isn't to hard to figure out how it goes back on.

The pilot is located in one of the holes that is off-center. You will probably need to look in the manual to figure out which. If you can't figure it out and/or don't have a manual, let me know and I'll look in mine. Or, you can guess and take it out and see if it looks like your new one (duh!).

You need a small screwdriver to get into the hole to remove the pilot.

That's about it. Remember to clean and oil (don't over do it) your filter while your doing all this unpleasant crap so you can maximize your roost boost! (clever eh?)

Did you get the YZ timing done correctly?

Good luck and let me/us know how you like the mod!



[This message has been edited by Bryan (edited 02-07-2000).]

Great info Bryan, until yesterday I'd never touched a carb. I changed the main jet on my YZ to a 180 (FMF recomended) to go with my new PC IV SA pipe.

Could you cross post this info on the needle jet install to the YZ side of the house?


Alright Chris, I posted the article on the YZ forum too.

Are you trying to get back at me for making multiple forums and categories?

Just kidding, excellent suggestion,


hi, I suggest you take off the whole carb. it's just 2 additional screws away and a few tubes. moreover you can have a look at your carb slide to see if it is giving way and at the same time clean your carb too. I find it's easier to work on a workbench than beside your bike. Check the accelerator pump too, it gets real gooey at times.

Thanks.I'll have plenty of time to do the needle change after i found out i fractured my right patella(kneecap) and minor ligament tears after i stalled my WR going over a 2 foot stepup.Oh well.Cant wait to go riding again.

That sucks Steve.

Get well soon,



I get at the carby by loosening the two boot screws, sliding the throttle twist grip assembly along towards the center of the handlebars. Then push the throttle cables through towards the carby near the center frame tube. I find that this allows me to rotate the carb in minutes. To remove carby do the same, then pull the air intake boot back off the carby and hook it behind the side frame tube.(compress the boot near the air box) This way you can get the carb out without removing or resetting the cables from the carb body. If you need more room you may remove the twistgrip housing completely and free that end of the cables.


Excellent tip Harry. I didn't think of that!

I want to be able to change jetting easily before rides to experiment and even taking off the cables is a bit time consuming. Your method makes it quick and easy.


I'm sure I posted this yesterday but!!!!

When I'm jetting I get the carb out by loosening the twist grip assembly and pushing it towards the center of the bars. If I need more room I open the twist grip housing and free the cables. I the push the cables through towards the carby. When I loosen the carby boots there is enough free play for me to get the carby out as far as nessessary.

To aid removal of the carby, grab the air box boot behind the frame tube and pull it back from there, that part of the boot is like a concertina thing. If you want the boot can be pulled right back to sit out of the way behind the frame downtube. Just make sure that you reattach the hot start tube to the air box boot after reassembly. Try it, it`s much quicker and less annoying.

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