All 2st Jetting Chat - Need Help? Post Your Questions Here

Hey guys, I decided to bite the bullet and bought a used 38mm Air Striker. I have been reading many posts about these carbs and some have mentioned removing the top throttle cable guide and replacing it with the curved one from the Mikuni. Now that I have Air Striker in my hand, I don't see how the brass guide can be removed from the screw on top. Also it has a 7 slide, which I think is most people have, the needle is R1368G. I have now idea if this needle will get me in the ballpark or not. Any help would be greatly appreciated!

Is this burbling?

I have that carb too and am using the curved metal guide from the mikuni on it. It unscrews from the top piece that it is attached to. You need to unscrew the locknut, then unscrew the whole thing. It will screw right into the top of the keihin. The reason for this was to avoid having to buy a new throttle cable.

My Jetting specs right now are:
09 WR 300
Keihin PWK 38
38 Pilot
JD red needle on 2nd clip
160 main
Elevations from at 5,000' to 10,000'
Temps from 70's to 90's F
Other mods: High comp head and Pro Circuit PC 2 pipe and type 296 silencer/spark arrestor. I also run a mix of race gas (110) and premium pump(91) with Bel Ray H1R ester based premix oil.

GiantJoe, that place you are riding looks awesome !!

Thanks, it is.

It sounds a little rich just off idle to me, my 144 did the same thing. I lowered the needle 1 clip position and it cleared right up on my bike, of course it all depends on what taper your needle is and pilot size e.t.c. try turning out your air-screw a quarter turn and see if it runs any cleaner at that same throttle opening. If you are already at 2.5 turns out or more on the air-screw then try the next size smaller pilot jet and set the air-screw to 1.5 turns out and adjust to the smoothest and highest idle from there and try it out.It took a lot of time and patience to get mine to run clean at all throttle openings but it was worth it!

Yeah, that's what I figured, too rich just off idle. I kind of let my air filter get a little dirty, so it only exasterbated the problem. I cleaned it tonight and will see how it runs tomorrow, but I'll be ready to adjust the air screw just in case...

It sounds just like my 10 300 at the moment, I was considering dropping the pilot as I adjusted the air-screw and made no difference. Bluddery at quart throttle but crisp in the rest. Righto off to order a 37 or 35 pilot..

I tried reading all 20 pages but I didn't make it, rode today, crashed alot and ready for bed. So, I apologize if this has been covered several times. I've got a 2011 WR300 with a PC Platinum 2 pipe. It has the Mikuni with 430 main, 45 pilot and a 6cfy5-74 needle on the second from top clip. Mid and top end are great. Low end is horrible. Air screw was 7/8 when I got it and is less than a 1/2 out now which was an improvement. I purchased it brand new and it already had the pipe on it. I didn't get any jets with it. I want to purchase some jets to play with the jetting but not sure what sizes I should get and if I should change the needle. Also, where is the best place to get them that will have them in stock?

Halls will have the jets and also different needles that you can buy without buying the whole kit and is pretty close to you.

Unfortunately, my reply won't probably show up for 24-48 hours. I tried Halls. Call twice and it was busy. Called again, put on hold for a few minutes, then hung up on. Called again and get a guy with an attitude and told me parts will have to call me back. That was 3 hours ago and no call back. Called Bill's MC Plus. Had my clutch lever I needed but not a 50 pilot I wanted to try. I don't see anyone else using a bigger pilot than a 45. I really don't have the funds to kick the Mikuni to the curb right now. Any suggestions? I really want to ride this weekend, but with it's horrible low end I can't make it up any hills without falling over several times before I make it to the top. My heavy, worn out KLX650R was better going up. Once again here are my specs:
Main: 430
Pilot:45
Needle:6cfy5-74 on the second from top clip
Slide: 5.0
Air screw: 1/2 turn

That doesn't sound like Hall's to me. Those guys are THE best dealer I've ever dealt with, period. Just worked with Jeff this morning and hung up praising them, as usual.

For jets, I've had great luck with http://www.pjmotorsports.com/ as well as my local Kawi/Yam/Suz/Hon dealer.

Wow, I apologize, my post showed up a lot quicker than others have in the past. Thanks for the link. My local dealers don't have squat regarding jets.

You can buy pilot jets and main jets from JD Jetting. You don't have to buy a kit since he doesn't have a kit for the 10 and newer wr's. He was a BIG help for me. I am not familiar with your' needle so I can't compare with my setup. But I am running a much smaller pilot than you. Look them up and ask for James.

Have you tried a smaller pilot or turning out the air screw? I think you may be too rich. I'm using a 27.5 on my 09 250. It didn't make good power off bottom and was hard to start even with the 30.

Giantjoe, if that's the stuff that you love riding, then l would set the jetting up for slow speed technical riding....forget the mainjet as you'll never touch it looking at that track.

Don't know too much about Mikuni's but l would grab, 2x pilot jets smaller than stock, possibly a JDJetting Red and Blue needle or the one's that the guys use in the Jetting DB and....l'd also grab a leaner slide.

Re: Halls...even from Australia their service is pretty top notch!!

PWK 38 AS: 7 slide, CEL needle in 2nd clip, 1st clip on very hot days, 38-40 pilot, 170-175 main.

Use a 6DEY15-74 needle in 2nd clip:=).

Well, a guy I was riding with saw me struggling and took it for a ride. He's been riding for 41 years, owns a MC shop and races hare scrambles on a 2T KTM. First thing he said after riding it was, now I see why you are having all that trouble. He was pretty adamant that it was lean. It was also running hot in the tight stuff with steam coming out of the overflow tube.

I'm usually not one to give a retail establishment a second chance, but since I was striking out finding jets and a needle I called Halls. It was a TOTALLY different experience. Extremely helpful. Unfortunately, no GAY needles, they are on backorder. I have a smaller and a larger pilot jet coming. I moved my needle to the middle and have the air screw about 1 1/2 turns. Just riding around the yard it seems much better. I'll find out this weekend.