RM125 carb mod keihin 38mm pwk air striker. what size jets?

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12/6/2017 4:13 PM

I have a 1992 rm125 mostly stock. No carb on it when i got it. I have a pwk air striker 38mm carb comining in mail im gonna put on but have no starting point to jetting this thing. What sizes should i start with as far as main slow pilot needle etc.... This bike is very clean for a 92. Ive gone over the whole thing. All is sound and in good order. New gaskets all over new piston ring new stator new boyesen dual action reeds coming in mail. I need help jetting this bike! Thanks!

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12/6/2017 4:17 PM

Btw bike will be running at 1100ft elevation and 40-60 degreez temp

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12/6/2017 4:27 PM

I had a 2002 rm144 and when I ran a pwk air Stryker it ran very poorly until I put a #4 slide in....it just bogged bad.

In would try the NOZI needle from a ktm 125 and use it's jetting starting point.

I remember the standard Kehin XYZ needles with a single taper would ping.

I've still got that slide and maybe a needle also

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12/6/2017 5:09 PM

From memory 50 pilot 180 main

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12/6/2017 5:41 PM

Tons of people use the NECJ needle out of the last gen RM250 (including myself in my ktm 200 and yz250). You'd probably want to start at 170-175 main and 40 pilot.

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2019 TX300
'10 200 XC-w

12/6/2017 5:46 PM

Hcallz5 wrote:

Tons of people use the NECJ needle out of the last gen RM250 (including myself in my ktm 200 and yz250). You'd probably want to start at 170-175 main and 40 pilot.

Yeah, that's a good idea....its similar to the NOZI and not one of the straight tapers that pinged

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12/6/2017 6:35 PM

IMO, Both the NOZI, and for sure the NECJ needles are too lean to be used in your 92' 125, especially for the temps that you have listed. I'll assume that the PWK has a #7 slide. The easiest way that you are going to get that bike to run cleanly is with a single taper needle. For the above temps, start out with a CCK needle, a 185 main and a 50 or 52 pilot jet, depending on the air screw. I don't know of any multi taper needles, that are still available, from an OEM that would work in your bike.

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12/6/2017 7:53 PM

Yeah the carb i ordered is set up as follows.... Main=170 pilot=55 48DDJ throttle needle and#7 slide

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12/6/2017 8:26 PM

Ryan_Glatz wrote:

Yeah the carb i ordered is set up as follows.... Main=170 pilot=55 48DDJ throttle needle and#7 slide

That needle will more than likely work, That DDJ is going to be a little bit leaner at the transition onto the needle, at right around 1/4 throttle, but it's off on the ends a little bit. I would drop the pilot to 50 and bump the main up to 178 as a starting point.

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12/6/2017 8:27 PM

i believe that is a single tapper needle... Im gonna get a handfull of brass and try some of these suggestions. Thanx again! Anymore input or tips?

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12/6/2017 10:37 PM

Photo

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12/16/2017 2:57 PM

Ryan_Glatz wrote:

Yeah the carb i ordered is set up as follows.... Main=170 pilot=55 48DDJ throttle needle and#7 slide

digger wrote:

That needle will more than likely work, That DDJ is going to be a little bit leaner at the transition onto the needle, at right around 1/4 throttle, but it's off on the ends a little bit. I would drop the pilot to 50 and bump the main up to 178 as a starting point.

Got it started. Idels ok. Revs good at lil short wrist flicks. Goose it and it bogs out dies. Put it in gear bogs out dies soon as i release clutch lever..... 178 main 52 pilot.... Sugjestions?

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12/16/2017 3:04 PM

Ryan_Glatz wrote:

Yeah the carb i ordered is set up as follows.... Main=170 pilot=55 48DDJ throttle needle and#7 slide

digger wrote:

That needle will more than likely work, That DDJ is going to be a little bit leaner at the transition onto the needle, at right around 1/4 throttle, but it's off on the ends a little bit. I would drop the pilot to 50 and bump the main up to 178 as a starting point.

Ryan_Glatz wrote:

Got it started. Idels ok. Revs good at lil short wrist flicks. Goose it and it bogs out dies. Put it in gear bogs out dies soon as i release clutch lever..... 178 main 52 pilot.... Sugjestions?

Mine dis that, then I ran the #4 slide

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12/16/2017 3:05 PM

It might never run well since 38mm pwk is a really big carb for an old 125

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12/16/2017 3:11 PM

Yeah but i should atleast be able to get it mobile

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12/16/2017 3:21 PM

Ryan_Glatz wrote:

Yeah but i should atleast be able to get it mobile

Lol. Not if it's too big a carb for engine.

You have two options, richer slide or smaller carb.

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12/17/2017 7:13 AM

Started up today fairy easy. Idles good air screw nearly all way in. Choke on idles with air screw nearly allway out. Revs good with air screw out 1\2 turn out. Slight bog on trans to needle\main.... My clutch plates are shot so cant tell how it will act under load.... This bike been nothin but headache since day 1!

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12/17/2017 7:15 AM

Air screw should be 1 1\2 to 2 out correct? So at 1\2 out indicates lean or rich? This carb shit is so confusing sometime

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12/17/2017 11:04 AM

Ok clutch cable adjusted now it moves. Plates are ruff but lil scuffing sanding. This thing is all top end! Bottom bogs but if i feather and ride clutch enough to get moving this thing rips at high rpm! Low end it wants to die.... Making progress.

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12/17/2017 4:24 PM

Hey I got a 04 rm 125 just purchased the keihin 38mm pwk air striker and wondering what the specs are for the main and pilot jet?

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12/17/2017 4:29 PM

Ryan_Glatz wrote:

Ok clutch cable adjusted now it moves. Plates are ruff but lil scuffing sanding. This thing is all top end! Bottom bogs but if i feather and ride clutch enough to get moving this thing rips at high rpm! Low end it wants to die.... Making progress.

It's wanting to bog and die off the bottom because the slide is too lean and/or the carb is too big.

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12/17/2017 4:32 PM

Ok update. Airbox has leak at boot. Sealed it off. Did plug chop... Chocolate brown.. main seems good. It is a monster on top end at 3\4 to wide open. But bogs and dies in gear at low rpm 1\4 throttle. In order to get goin i have to rev it high with clutch in and slowly ride clutch at high rpm. Pull clutch back in to save from bogging out dead. Release easily slowly bogging into speed untill hits power band then it is scary fast and kicks ass! I think eed to adjust pilot or needle clip...... Anyone else got ideas?

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12/17/2017 4:35 PM

Bruce372 wrote: Photo

Would you consider selling the slide? You ever find that needle?

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12/17/2017 4:37 PM

Btw it seems to help the bogging if i choke it

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12/17/2017 5:24 PM

Bruce372 wrote: Photo

Ryan_Glatz wrote:

Would you consider selling the slide? You ever find that needle?

Give me a couple of days and i will try my best to find the needle. I will happily sell that slide, if it doesn't help you can ship it me back. Text me 858 775 two two 31

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12/18/2017 11:23 AM

Hey I have 2004 Rm 125 and ordered a 38mm keihin airstriker not jetted to my bike. And can’t find any jetting specs for my bike. Can anybody help me out?

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12/18/2017 11:34 AM

Danny_Morris wrote:

Hey I have 2004 Rm 125 and ordered a 38mm keihin airstriker not jetted to my bike. And can’t find any jetting specs for my bike. Can anybody help me out?

I ran a NOZI needle and the #4 slide, this was a 2002 rm144. For jets inwpuld start 50 pilot, 180 main

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12/19/2017 7:50 AM

Im getting a bog on takeoff thought it was lean raised needle lowered clip but then it reved uncontrolably high at slightest twist of throttle and took seconds to settle back to idle so i lwered needle raised clip to second from top and now it starts out decent but bogs at half throttle 52 pilot 178 main if i stay at 1\8 1\4 throttle it accelerates good and once at high rpms power kicks in but im getting flat bog if i juice it hard like it runing out of gas or too much air....

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12/19/2017 7:52 AM

It may be the slide since its in the 1\4 to ³\4 throttle range.........

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12/19/2017 3:37 PM
Edited Date/Time: 12/19/2017 3:41 PM

Danny_Morris wrote:

Hey I have 2004 Rm 125 and ordered a 38mm keihin airstriker not jetted to my bike. And can’t find any jetting specs for my bike. Can anybody help me out?

Yeah go with the 180 main if its cold where you are. I have 178 main in my rm125 with.pwk38mm.keihin.airstriker.and its running lean i have the needle clip in the middle and a 55 pilot. It runs pretty good with the air screw almost all the way in. My airbox was faulty so i took it off left the boot and stuck a big foam filter.in.the.hole.taped half the opening closed so its not getting too much air. And now it is running much better! Its still lean but im pretty sure one size up on the main will fix that. Once i get the new.airbox ill have to start jetting.it.all over again.....

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