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

COFFEE EDIT: HuskyDude the ever helpful moderator is attempting to make the 2st jetting thread more useful, the rest of this message is from him - not JohnnyMannen. Sorry for any confusion.

In a attempt to get the Jetting thread back to basics. Jetting info only. I'll will This new thread called Jetting Chat and will move some of the post over. It will make it easier for anyone looking for Jetting Info later. Trying to go through 9+ pages of info while looking for a specific bike will be hard.
Please post your Jetting story's and things in here.

Thank You.
HuskyDude

Thanks bud!

I'm sure it can get better than the N3EJ, but that's the leanest one I had. I cannot believe what a difference it made. Feels like the bike picked up 5hp from my built in ass-dyno.

Now I'm really jonzin' to ride again

I received my Keihin PWK 38AS from Kelly 2 days ago and has installed it on the bike and went out for some streetdriving today. it´s definetely more power from low revs and more direct on the throttle. I started with the jetting that was installed: 45 pilot, blue JD needle in 3rd clip, 175 main and airscrew 2 turns out. I live at sealevel and we have about 50F here. Bike starts fine. I noticed that it was running rich at very light throttle(bluddering) and started to run clean and crisp as soon as i gave some more. Very linear and nice power curve. I tried to get rid of the lowend bludder by lowering the needle one clip, but that didn´t help much. This appears when i lie on constant throttle on the road.When it was idling it just died. I had to change plug to start it again and the plug was wet. I think i will try a 40 pilot to see how this will affect it. I turned the airscrew out 3 whole turns, but it didn`t help against the bludder. I also wonder in what way the red needle from JD is different from the blue? Anyone knows? It´s a lot of light throttleuse on the street, so running rich get´s very obvious.

Johnny

More jetting info from Sweden. This jetting that follows is made on the street with Motardwheels and focused on to get the bike to run as smooth as possible at small throttleopenings. Now i have changed needles and clip positions all afternoon! I wanted to evaluate the blue and red JD needles. I started with changing my 45 pilot jet as it was too rich. The bike was running hard on idle and died by running too rich. I changed to a 42 and it was much better. Now the engine "rolls" smoothly on idle and sounds softer with improved throttlerespons. I also changed clip position on the blue needle to second from top to se if this would take the bluddering at light throttle away. It was a very slight improvement, but not satisfying. I decided to try the red needle and started with middle clip position. Slightly better. Another change to second from top was great powerwise! Very crisp respons and felt really strong on throttle! Also slightly better from very light throttleopening. Less bluddering. My last test was to try the clip in first position(leanest needle in leanest position) and this was the best for street use if you want smooth driveability. There is still a small bluddering as soon as i open the throttle, but it´s much better now then with the blue needle in 3rd as it was from the beginning. The bike has a very crisp throttlerespons and sounds really clean and crisp on throttle too. The bike is not so aggressive at throttlopenings and feels very controllable as soon as i twist the throttle. It doesn´t seem to loose much power even running this lean. Feels really strong! I think this would be a nice setup for the woods too. Seems like the Husky likes to run quite lean. This must be quite lean as we have about 50F and i live at sealevel. I will try to go one step leaner on the pilot to a 40 to see if i get rid of the slight bludder right off throttle. My conclusion of this is that if i ger rid of the slight bludder right off idle wth a smaller pilotjet i think i would use the red needle in second position. I run 3% oilmix 98 or 99 octane fuel. I have 175 mainjet. Now i change needle in 4 minutes too
Any comments to this is welcome!
Johnny:sweden:

Ok Kelly, so you think that would clear up the slight bludder at throttleopening? I have the 170 main to put in. Do you think that´s ok so i wont go lean? The plug looks good, light grey in the middle ceramic. Could it be the slide that affect this? It´s running clean at very low revs but starts to bludder slightly as soon as the revs are creeping up and i have the throttle in the same position.I often hear that people say that the needle doesn´t affect the mixture at small throttleopenings, but i can feel that it does, just like you say too. I think it´s very intresting to learn about jetting and what does what when it comes to jetting!

johnny

Ok, now i have tried different jettings on my PWK 38 AS to try to get rid of the light "highway throttleopening bludder" that i have at constant light load on the road. Nothing is making any difference. I have tried to lean down the needle, smaller mainjet and smaller pilotjet. I currently have the red JD needle in 2nd clip from the top, 175 main and a 40 pilot in it, and it´s crisp as hell as soon as i start to give it some more throttle. Could i be that i need another slide? Has anyone tried one? Could it be the starter jet that is too big for streetuse? As a comparison me and my friend who has a KTM EXC 300-2008 did a WOT in fourth gear from quite low revs and he was clearly left behind! So much for adjustable exhaustports!

WR300 jetting

Now you leaned off everything else,have you tried the air-screw again?
-After all I've read,I think the Keihen is on the cards for me.

Yes, i have tried the airscrew, but i get lean on idle if i pull it out more. A s i have a 40 pilot now that is on the limit of being lean already. maybe i could get it better if i put a 42 pilot in and lened out on the airscrew? I also tried 2 KTM needles today, N2ZW that was fat as me in wintertime and one named N84K i think, and that one was very smooth on light acceleration, but still bluddered a constant throttle and made it less powerfull. The best so far is the red needle in highest clip position for road use.

One thing often overlooked that is simple and allows for richer settings to avoid the bottom end blubber are more slide cutaway. Slides are also easy to change out for air-fuel ratio.

Are you pretty sure your compression is good?
I tried to get rid of an off idle blubber for quite a while (WR250). Ended up with a 40 pilot and after numerous needle changes still had the blubber, though not as bad. Finally discovered my compression was low and had to do a cylinder replate. I haven't had it up in the woods but around the track at home it runs great.
I bought the bike used, so I have never known what I had bought until now. Very impressive, but smooth power hit and very crisp. I find myself farther forward to keep the front end down, so I may try a 42 pilot to mellow things a tad. We'll see, it runs so good I hate to change anything and where I usually ride there is more elevation so ... might be good.
I don't remember which needle is in there now, so I'll post my stuff later.

I bought my bike new before Christmas and have maybe around 40 hours on it, so i don´t think it,s the comp. It´s not much bludder, its just that it becomes very obvious when i´m on very light throttle on the road. I guess this is hard to get rid of on a woodsbike. It´s always intresting to learn and experiment!

Johnny

Johnnymannen, before today my bike also bluddered at constant throttle but now my bike is PERFECT

I have put a POWERNOW PLUS on it today and i cant believe it !!!
This small piece of metal @ $100 (it would cost $5 for product it) worth every $$$ B Before, my bike have a slow response in trottle and it feel not strong enough at low rpm. Also, it have this same trouble in constant speed that you comment. Now my bike have instant trottle response and the bluddered is gone.

I feel my jetting PERFECT, very crisp and very clean. Even at $100, this small thing (powernow plus) is a real deal

I liked the Power Now on my last two Mikuni TMX's and would like to put one in my PWK. Do you have the Part Number for the Power Now application for the PWK 38 AS?
Thanks,
Norman

Yes, the Item code on my invoive is PNP38PWK A/S.
The description is: 00-09 YZ250, 00-08 KX 250, 01-08 RM250
03 KTM 300MXC, 00-04 GasGas EX 125/250/300
TM Enduro 250. 08 Husky CR125

This is for the Powernow Plus.

Hello canadian man! Maybe i should try the Powernow then. I´ve heard that some guy had problem with delivery. I guess i have to take that chance! What was your jetting besides th Powernow?

Johnny

Hello canadian man! Maybe i should try the Powernow then. I´ve heard that some guy had problem with delivery. I guess i have to take that chance! What was your jetting besides the Powernow?

Johnny

Ok, thanks! I´ll order the parts tomorrow! Always intresting to laborate with the jetting!

Johnny:sweden:

Can we pin this to the top?

Anybody have a 2009 WR 250 with the stock carb and know there jets?. I have a friend with one of these bikes and is riding at about 950 feet elevation.