Author Topic: Keihin PWK 38  (Read 11691 times)

0 Members and 1 Guest are viewing this topic.

Offline Paul552

  • Legend
  • *****
  • Posts: 672
  • HEAVEN #552
    • View Profile
Keihin PWK 38
« on: August 28, 2015, 08:55:28 pm »
Can anyone ID this PWK38 it has PWK 37E2 on it?
It has the 4 vents on it and also a cable off the side of it?

I bought it to fit on my 89 cr 250??
Can I use it on the 89? What to do with the wires?
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F

Offline Nathan S

  • Superstar
  • ******
  • Posts: 7275
  • HEAVEN #818
    • View Profile
Re: Keihin PWK 38
« Reply #1 on: August 28, 2015, 09:02:55 pm »
Wires are an electronic power jet. Good thing if you have a CDI to drive it.
Most likely from a late 90s KX250.

Ignore the wires, jet to suit.
Or buy a programmable ignition that can drive the power jet, and really make it sing.
The good thing about telling the truth is that you don't have to remember what you said.

Offline Paul552

  • Legend
  • *****
  • Posts: 672
  • HEAVEN #552
    • View Profile
Re: Keihin PWK 38
« Reply #2 on: August 28, 2015, 09:30:59 pm »
Thanks Nathan
Can I just unsrew it and cap it?

Also what's the difference between pwk38 and PWK "airstriker" ?
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F

Offline MRMOTORCROSS

  • C-Grade
  • **
  • Posts: 51
    • View Profile
Re: Keihin PWK 38
« Reply #3 on: August 28, 2015, 09:43:42 pm »
air striker carb has ridges or fins in the back of it on the airbox side, they are a better carby.

Offline Paul552

  • Legend
  • *****
  • Posts: 672
  • HEAVEN #552
    • View Profile
Re: Keihin PWK 38
« Reply #4 on: August 28, 2015, 10:01:54 pm »
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F

Offline Paul552

  • Legend
  • *****
  • Posts: 672
  • HEAVEN #552
    • View Profile
Re: Keihin PWK 38
« Reply #5 on: August 28, 2015, 10:03:07 pm »
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F

Offline Paul552

  • Legend
  • *****
  • Posts: 672
  • HEAVEN #552
    • View Profile
Re: Keihin PWK 38
« Reply #6 on: August 28, 2015, 10:04:24 pm »
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F

Offline Paul552

  • Legend
  • *****
  • Posts: 672
  • HEAVEN #552
    • View Profile
Re: Keihin PWK 38
« Reply #7 on: August 28, 2015, 10:07:50 pm »
Couple of picks.
Would jetting be simliar to the stock PJ38?
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F

Offline smed

  • Legend
  • *****
  • Posts: 1646
    • View Profile
Re: Keihin PWK 38
« Reply #8 on: August 28, 2015, 10:10:55 pm »
I will be interested in what you think of the swap out Paul,I am thinking of putting a PWK on my 85 CR125  :)     http://www.ebay.com/itm/New-KEIHIN-PWK-38mm-PWK38AS-S66-AIR-STRIKER-CARBURETOR-TRX250R-CR250-LT250-Carb-/171854376056?hash=item280351ac78&vxp=mtr

From China??????? are these the real deal,they sure look like it :-\

Offline Paul552

  • Legend
  • *****
  • Posts: 672
  • HEAVEN #552
    • View Profile
Re: Keihin PWK 38
« Reply #9 on: August 28, 2015, 10:20:26 pm »
Smed They look the goods that's for sure.
I have a 84cr250 that runs perfect and a 89cr250 that is awful off idle just can't get it clean with the PJ. As a result I just don't like riding it. Everyone says the PWK is better so I thought I would try it when one come up.
I didn't realise this one had the tps till I bought it.
Might try it with the PJ jetting as a start point
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F

Offline Lozza

  • Legend
  • *****
  • Posts: 4206
    • View Profile
Re: Keihin PWK 38
« Reply #10 on: August 29, 2015, 12:00:35 pm »
Can anyone ID this PWK38 it has PWK 37E2 on it?
It has the 4 vents on it and also a cable off the side of it?

I bought it to fit on my 89 cr 250??
Can I use it on the 89? What to do with the wires?

The worst that can happen is if you don't plug the passage in the float bowl the engine will run rich after peak power. The solenoid is there to shut the fuel flow when switched on.
Jesus only loves two strokes

Offline Paul552

  • Legend
  • *****
  • Posts: 672
  • HEAVEN #552
    • View Profile
Re: Keihin PWK 38
« Reply #11 on: August 29, 2015, 01:07:17 pm »
So lozza better keep the solinoid in place?
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F

Offline Paul552

  • Legend
  • *****
  • Posts: 672
  • HEAVEN #552
    • View Profile
Re: Keihin PWK 38
« Reply #12 on: August 30, 2015, 09:40:19 pm »
Does anyone have any advise on jetting the PWK?
On the PJ I'm running 45 pilot 178 main 1369 needle on second clip.

Is jetting similar?
'77 YZ125D '84 CR250RE '89 CR250RK '84 CR80RE  '09 YZ250F

Offline Nathan S

  • Superstar
  • ******
  • Posts: 7275
  • HEAVEN #818
    • View Profile
Re: Keihin PWK 38
« Reply #13 on: August 30, 2015, 10:35:02 pm »
In my experience, you'll go a fair bit leaner on the pilot, but main jet will be about right.
The good thing about telling the truth is that you don't have to remember what you said.

Offline Lozza

  • Legend
  • *****
  • Posts: 4206
    • View Profile
Re: Keihin PWK 38
« Reply #14 on: August 31, 2015, 12:11:10 am »
So lozza better keep the solinoid in place?

You can't really remove the solenoid itself. IIRC there is a jet underneath that could be soldered up. Does the brass tube in the carb throat go all the way across like in the pic above?  If yes thats not normal.
Jesus only loves two strokes