Needle Location Kehin

[teirboss]

Hello. I just finished rejetting my carb on my 01 ex. I tried to change the pilot to a 42. I could not get it to thread in. After comparing the stock jet (38) to the (42) I could see that the 42 was much thinner on the threads. Any one know whats up with that. Also, does any one know the location of the needle. I want to raise it (lower the clip setting one) to increase fuel. I just installed a 165 main jet. I was running lean.. Thanks....

[knighttime]

If the threads dont match up, you have the wrong style pilot jet.

[Scott]

The needle runs down through the center of the slide. If you removed your carb from your bike, the parts you're looking for are probably hanging on the end of your throttle cable...

[4punksdad]

not on the 400ex..........the throttle cable attaches to the side. I had mine apart a few times,,,,,,,,,but I was cleaning the bowl & never looked for the needle. just tear into it. its a carb, there aren't that many moving parts! sorry I cant help more.

I went to my dealer today to get a #42 pilot jet for my EX, and his parts fiche doesn't list one. Anybody have a part number or is aftermarket the best shot? There seem to be two kinds of Keihin pilot jets. Anyone know whidh one to use??

To change needle clip posistion pull side cover off of carb, remove top of carb, under top you will see the slide & the lever that attaches it to the linkage, I remove the screw that attaches the arm to the throttle linkage ( closest to the eng side of carb ) then you can gently pull the linkage out ( looking at carb from throttle cable side it's in the very upper right hand corner) pull the linkage out just far enough to lift the arm up & out ( there is a spacer washer here also just pay attention where its at, its easy to reinstall) now you can just pull the whole slide assy out of the carb. when you look inside the slide you can see 2 small phillips screws, remove them both & the needle is just under neath.
It sound complicated but if you remove the gas tank (or just prop it up a couple of inches it can be done in less than 10 minutes & you dont have to remove the carb or worry about stripping out the heads of the phillips screws.
To get the correct pilot jet take the old one down to match it up, & try some mx accesorie stores or someone who tunes mc engines, I never have any luck at the dealerships with different size pilot jets. They only ever have the mains.

[Scott]

Thanks for the corection 3punksdad, I guess I'm used to my older bikes.

[4punksdad]

Originally posted by Scott
Thanks for the corection 3punksdad, I guess I'm used to my older bikes.

the ole slide carb is a simple & effective design isn't it? :)

[Scott]

the ole slide carb is a simple & effective design isn't it?
Yep. If it ain't broke, don't fix it.
Having never run a flat slide or any other aftermarket carb, I never understood where the gain came from just by changing the shape of the slide.

I'm also not sure what the advantage is of a linkage operated slide or a vaccuum operated slide.

Alinkage operated slide give instant throttle response, A vac operated slide has to wait (if only for a milisecond) for a vvac signal, also on a linkage (flatslide) carb there is nothing in the carb bore but the slide & the needle, whereas on a vac carb there are usually 2 butterfly's(1 for the choke & 1 to control air fuel) the slide & the needle. Less obstructions = more & faster air/fuel flow = better throttle response & more power.

[Scott]

Thanks for the response, but if you read what I posted, that wasn't my question. I know HOW a vac slide works, I own one on a Wolverine. My questions were How does the shape of the slide benefit the performance and why go from a directly connected slide to one that is either linkage or vac. style? You're not going to convince me that connecting via linkage gives quicker response than having the throttle cable dirctly connecting to the slide. And vac. operated is always going to have a small lag compared to mechanical activation.