PWK 39 Jetting Problem (Upgrade from PJ 38)

[MurderCycle]

I have a 97 CR5 w/a stock PJ 38 jetted a little fat for the Oregon dunes (180 Main, 60 Slow Jet, 1.5 AS out). It would spooge black goo from where the FMF TurbineCore II silencer mated w/the FMF Gnarly pipe, but I thought a little rich could save me from a siezure, which I'd accomplished two times before running lean.

I just moved to Anchorage, AK and have been riding at a local track (ride right out of the garage less than a mile down the road) and decided to upgrade my carb to a PWK 39. I haven't cracked it open, but I was told it is shipped pre-jetted at 170 Main, 55 Slow Jet & 1.5 AS out. While I'm still at sea level, average temp right now is 65 degrees.

I can't make this carb idle ... even if I screw the idle in pretty tight. I'm thinking about throwing in a 50 Slow Jet and see what happens.

BTW, it runs really good mid to high power band ... just won't idle and sounds a little boggy at the bottom.

Let me know what you think!

[ou812]

48 to 50 should be about right with a stock motor

[MurderCycle]

So, do you feel 48-50 is a normal SJ starting point for a PWK 39? It just seems strange my PJ 38 idles well with a 60 SJ and going to a larger carb requires a significantly smaller SJ.

But, if it doesn't idle, it doesn't idle.

Question: When you're going through jetting a bike, do you keep the carb on the bike (loosen clamps, rotate & drop the bottom), or do you loosen the sub-frame and pull the carb off?

Thanks for your help!

[ISBB]

i usually pop the slide cap off then rotate in the clamps... I found out the hard way that mine wont rotate with the cap on there

[AlisoBob]

http://www.bannedcr500riders.com/board/ ... c.php?t=92

Read Grasshopper, read.

[ou812]

Yep just spin the carb, it's way easier. The reason the PWK uses smaller pilots jets is it has a better draw aka a better signal at idle and low throttle settings.

[4Z]

Would that be Kincade (SP)? When I lived there I notice that on most days there was very good dense air there. Loved the track, back then it was the only one in Anch.

[MurderCycle]

Thanks for the advice ... and the link! I'll dig in.

And, yes, the track I'm riding in Anchorage is Kincaid Motocross Park. It sits right on Cook's Outlet ... long ... lots of tabes ... and lots of rocks! On the upside, the track is maintained by the city and worked over by two onsight Cats weekly. All for $175 bucks membership per year ... which is optional. I guess this is another perk for living in a government rich oil state.

The kids think I'm riding a dated 250 ... they don't know what the hell a 500 is. But, the older guys, like myself, get a good horsepower giggle out of it. And, the kids wonder how I keep lobbing 5lb boulders at their knuckles!

[100hp honda]

sudco should know the pwk39 better than anyone..i dont understand why they would send it with 55 in there . they sent mine with a ECA needle . the bike barely ran

[dannygraves]

thats the default from keihin, thats why...

[MurderCycle]

I found this info on "another" site ...

Base line for Service Honda CR500AF with 38 and 39 PWK. These were obtained from AJ himself.
Main - 175
Pilot - 55
Needle - 1368N 3rd clip position
Slide - 6.0
AS - 1.5 turns

As for my fix, I have a 50 Pilot that I'll test out tonight and hope I can find an idle (replacing the existing 55)

[AlisoBob]

I found this info on "another" site ...

Base line for Service Honda CR500AF with 38 and 39 PWK. These were obtained from AJ himself.
Main - 175
Pilot - 55
Needle - 1368N 3rd clip position
Slide - 6.0
AS - 1.5 turns

As for my fix, I have a 50 Pilot that I'll test out tonight and hope I can find an idle (replacing the existing 55)

Much of jetting depends on temp and elevation. That said, the pilot and needle are fairly rich for that main jet size.

NO ONE can jet your bike over the phone, keyboard, or your buddies "Hot tip"..... Those $80 JDJetting kits are a joke...

You need to learn to do it yourself...

[MurderCycle]

Well, I just cracked open the new PWK 39 to replace what I thought was supposed to be a 55 Pilot ... it turned out to be a 60! Bastards! So, I figured installing the new 50 would be perfect ... maybe even a little lean. With the idle screwed all the way in, the AS 2 turns out, I still can't get an idle. It sounds crispier than it did before, but it still won't breath on it's own.

With this being said, what do you think is a good assortment of Pilots I should pick up? Maybe a 45, 40 & 35? You have to keep in mind I'm in AK, and picking up parts can be a BEEEOOOTCH! My local Honda shop doesn't even stock CR5 air filters, or Pilots for that matter. I found an ATV mech shop 12 miles out of town that has an OK jet selection.

[ISBB]

if the honda shop doesnt stock kehin jets you need to find a new shop.. The majority of kehin jets are all interchangeable between carbs.. hell the ones in your pj should fit as well. Also make sure they are the authentic kehin jets that have the little star etched into them.

[MurderCycle]

You must be in CA ... no offense. The next closest Honda shop is thousands of miles south in a town called Seattle. I'm in Alaska! I can't count on the super market having limes in stock, let alone a bike shop stocking pilot jets! TIA ... this is Alaska.

[ISBB]

actually im in nevada however if its a honda shop they should have a selection but ya do whatcha gotta do.. When i bought my bike i bought mains everything from 170-210 a needle and a few pilots cost me like 30 bucks from sudco.. I would call up sudco and see if they could hook you up with and assortment i would start at 35 - 60 and the same with mains you can never have too good a selection. Spend the 40 -50 bucks on an assortment of genuine kehin jets and needles and you will be set for quite a while and for any elevation or temp changes you need to make

[AlisoBob]

Spend the 40 -50 bucks on an assortment of genuine kehin jets and needles and you will be set for quite a while and for any elevation or temp changes you need to make

Solid!

[aloha450x]

since we are on the subject. pwk39
dgn 40 pilot and 175 main. is that a good place to start at sea level.

[M.F.D.B.]

Theres a bunch of places here in Vegas that stock genuine Keihin jets. If you want I can pick you up an assortment of pilots and mains and ship them to you...

Needles are pretty much a special order only anywhere you go. There is simply way to many possible combinations for anyone to stock them. You could start with a DGN, which works well for me, or maybe just a bit fatter in the mid/high.

My bike wont idle with the spring on the screw. I have to thread a metal (not the stock plastic) idle screw in to hold the slide open enough for idle, which means I need a bigger slide then 6.0. Prolly the case for you as well. If you have to just slightly hold tension on the throttle to get it to idle then this is prolly the case...

[MurderCycle]

Thanks for the offer, M.F.D.B.! I may take you up on it. I'll make a pass by my jet source to see what they have in stock and let you know if I can use your assistance.

It was mentioned earlier that no matter how small the pilot, a after-market idle screw was the only way to attain an idle. I've never heard that before Is that a band-aid, or a real possibility?

[M.F.D.B.]

Technically its a bandaide. You need a larger slide cutout. But the metal screw like you are talking about, that I use, is much cheaper!! Plus its piece of mind as well, since the stock plastic screws are real flimsy...

[M.F.D.B.]

since we are on the subject. pwk39
dgn 40 pilot and 175 main. is that a good place to start at sea level.

My bike wouldnt run on such a small pilot. I run in the 50's at sea level...the rest will be close if you arnt far from stock...

[AlisoBob]

since we are on the subject. pwk39
dgn 40 pilot and 175 main. is that a good place to start at sea level.

Normally ,no. BUT... with the humidity in Hi, I would say yes.

[MurderCycle]

I ended up getting an idle with a 38 Pilot, air screw 2 out and idle crew pretty much all the way in. I Main that came with the new carb, which was supposed to be a 175, turned out to be a 160! Geeez ... that could've burnt me up! It pays to double check.

So, I swapped out the Main to a 175 and she's running pretty crisp.

Compared to the stock PJ 38 there's quite a difference: quicker and crisper fuel delivery, smoother power delivery from mid-low through a high-end that I've never had access to before. It's strange for me to ride a 5 that rev's high. I've got to learn when to shift all over again. And on the track those jumps come at me REALLY fast.

The only negative that I feel is a slight loss of low-end ... almost like a lack of torque down at the bottom. I did change from a PowerCore II to a TurbineCore II which could account for this, but I don't know. It could also be only my perception ... who knows.

GIVE ME SOME INPUT!!!! WHAT DO YOU GUYS THINK?

[AlisoBob]

The only negative that I feel is a slight loss of low-end ... almost like a lack of torque down at the bottom.

You need a leaner needle, or at least raise the clip.