Author Topic: Pwk vs. Pj  (Read 5795 times)

0 Members and 1 Guest are viewing this topic.

Offline toomany

  • Full Member
  • ***
  • Posts: 50
Pwk vs. Pj
« on: September 18, 2009, 03:59:40 PM »
I've got a Keihin Pj on my K5 (guy I got it from said it was a Pwk). I'm guessing it's off of a Cr500. Looking around on ebay I'm finding a few (Pwk's) that are a decent price. Is the Pwk any better than the Pj? I know the Pwk has a better idle adjustment system. But other than that is there much to be gained from switching? Currently my K5 will idle for a few seconds then die. Does anyone know if a carb switch would help this? I've got a bunch of jets for the Pj, but they interchange with the Pwk so that's a plus too.

Offline Friar-Tuck

  • Hero Member
  • *****
  • Posts: 1,827
  • \o/ Live Free or Die
Re: Pwk vs. Pj
« Reply #1 on: September 19, 2009, 09:45:54 AM »
  Toomany,
     The stalling condition may have one or more issues associated with it.
 Stuff you may want to check,  Fresh fuel, clean air filter, reeds in good shape, carb slide not scratched or chrome worn off where it rides in carb body, jets and bowl clean, and the choke idle circuit for dirt and scratches.
I've seen two PJ choke/idle pieces broken, wouldn't raise or lower the "needle" in the idle circuit  as you turn the "knob" on top of the choke.

I think you'll find most of the guys with PJ's are looking for a PWK.
  Something to consider is what type of riding are you doing, and how hard are you riding.
 
  I had a PJ on my '85 CR and it was fine for trailriding/single track for me.
I did have to replace the slide, choke,needle and jets.
 The old girl was tired, but she had a great body.  (that just doesn't sound right)
Anyway, if the body of the carb isn't too bad you can re-build it.
    http://www.sudco.com/

Unfortunatly, it's almost as much as the new PWK.
     
I also have a PWK 38AS (air striker)   http://www.keihin-us.com/pwk.htm
 PWK Air Strikers: Directs air to main nozzle for improved signal and throttle response.
     Great low end throttle response at the loss of top end.

I got the 38 a.s. used, quite a bit less than a 39.5.   
       The Air Striker worked  best for me,  (single track woods etc.)  But I rarely get a chance to run WOT very long ....
 
   I don't have a  PWM or Lectron Etc. so I can't comment on them, but something else you may want to consider. 
  Tuck\o/
"The Truth Has No Agenda"

Offline toomany

  • Full Member
  • ***
  • Posts: 50
Re: Pwk vs. Pj
« Reply #2 on: September 19, 2009, 11:18:24 AM »
Thanks for the help.

The fuel is always fresh in my bike, same with the air filter. The reeds were just replaced....maybe 6 hours on them. The jets are all new/clean, same for the bowl. The needle/seat and float are also new. The choke circuit is clean and works properly (screwing the choke knob up or down will alter the idle). The slide has a wear pattern in it, but the chrome is still there. There isn't a groove that I can feel...but I'll look into it.

I mainly ride single track trails and hit the dunes a few times a year. I'm not looking for a monster on the top end, just something that runs good throughout the RPM range. I've got it dialed in to my liking, just not the idle. A crisper throttle response would be nice, may look into the Airstriker. I was just currious if the Pwk was worth the investment over my current Pj.

Offline DoldGuy

  • Hero Member
  • *****
  • Posts: 1,198
Re: Pwk vs. Pj
« Reply #3 on: September 19, 2009, 02:38:38 PM »
Toomany,
According to Eric Gorr, the PWK makes 3 more HP on the CR500 versus the PJ. The PWK is my personal favorite & fairly affordable.
Its Never too Late to Have a Happy Childhood!

Offline PowerFiend

  • Full Member
  • ***
  • Posts: 169
Re: Pwk vs. Pj
« Reply #4 on: September 29, 2009, 12:10:59 PM »
Toomany,
According to Eric Gorr, the PWK makes 3 more HP on the CR500 versus the PJ. The PWK is my personal favorite & fairly affordable.

Remember that the carb Gorr is recommending is the KX5 pwk, which is a 39.5mm vs. the stock 38mm PJ. I think the PWK with the separate idle adjust is a better carb, but 3hp seems excessive. Now if he is talking about 3HP with the carb and the port mods he recommends, I can see that. His port mods raise and widen the exhaust port, which shifts the power up.