Page 1 of 1

38mm PWK

Posted: March 17th, 2012, 4:32 pm
by lerea3
Anyone running a PWK 38mm Air striker at around 3200ft? I got my top end back from Roosty and added V-Force reeds, FMF pipe/silencer and new carb. It came with 170 main, 55 pilot, clip in the middle. Once I got it started the bike will not idle. Searched through the jetting threads and Bob posted a comment stating the idle screw needs to be turned all the way in on the PWK. Well the plastic idle screw is junk!!!! One side of the screw broke off :evil:
After running the bike for 10 minutes I had spooge coming out of the silencer already.
If its ok with Bob, I would like to start a sticky so guys like me don't keep asking "what jetting are you running" I'll start

Carb-38mm Air striker
Altitude-2600 to 3800ft
Temp- 70 to 80 degrees
Main- 170
Pilot-52
Needle-DDJ
Clip position-3rd
Degree of satisfaction- seems rich, spooge out of silencer.

I realize there is a ton of variables when it come to jetting, but this might help guys out to start with.

Les.

Posted: March 17th, 2012, 8:05 pm
by dannygraves
go leaner on the pilot. most 500s like 45-50 on the pilot in a pwk.

Posted: March 17th, 2012, 8:17 pm
by lerea3
I tried a 45 and had a hard time starting it. Once I got it running it still won't idle. I will pick up a 48 and a 50 to try. I tried to adjust the throttle cable so it would at least idle but I was maxed out on the adjuster.

Posted: March 17th, 2012, 8:42 pm
by gregrobo
Where is your air screw at,half to 1 and half turns out
Try the 50 and adjust it

Posted: March 17th, 2012, 8:46 pm
by lerea3
1 1/2 out

Posted: March 17th, 2012, 9:44 pm
by gregrobo
Does the air mixture screw change the idle any

Posted: March 18th, 2012, 1:55 am
by johnnytheswede
I see that you are using a very short needle. It's also quite rich at the base diameter with it's J size number. I would prefer to use a DGL or DGM needle at your elevation and temp and try it in 3rd clip position (middle) together with a 48-50 pilot jet, just like said earlier.

Johnny

Posted: March 18th, 2012, 7:11 am
by lerea3
Gregg, I couldn't get it to run without giving it some throttle, so I was not able to play with the airscrew much.

Thanks Johnny, I will try the new needle and pilots.

Posted: March 18th, 2012, 9:59 am
by AlisoBob
Snip off a few turns of the spring, to get the idle speed screw in deeper.

Posted: March 18th, 2012, 10:11 am
by lerea3
I will try that Bob. That plastic screw is weak. I was adjusting it and one side of the head broke off.

Posted: March 18th, 2012, 10:14 am
by AlisoBob
The way to adjust it is to open the throttle, turn the screw, and close the throttle.

Keihin makes a brass replacement one.

Part # 1034-826-2002

http://www.hyperracing.com/Assets/Hyper ... 20Carb.pdf

Item 29-A

Posted: March 18th, 2012, 5:07 pm
by seanmx57
I'm making my own. bearoso turned me onto the trick, kudos to him.

Get a 5mm bolt and a 5mm wingnut. grind the tip of the bolt to the same coutour as the tip of the plastic crap. locktite wingnut to head or double nut the wingnut so that you can udjust the idle with no tools very easily. Should cost less than $5 in stainless steel.

I'm not sure if it's 5mm just take the plastic one to the parts store to match thread.

Get your self a zip ty AS while you are fiddling around or make your own. you can adjust them without tools as well. Got the tip from bob. It's very handy to tweak them by hand as needed.

For instance I crank the AS in 1/2 turn to richen the mix for starting along with the choke. Once it's been running for a minute I'll put it back where it was.

Posted: March 18th, 2012, 5:29 pm
by lerea3
Thanks for the replies! I will be ordering jets and needles tomorrow.

Posted: March 18th, 2012, 6:26 pm
by AlisoBob
seanmx57 wrote:Get your self a zip ty AS while you are fiddling around or make your own.
Yupp... one of the best mods you can do.

Image

When you have the correct pilot jet, this adjustment becomes very sensitive.

Posted: March 19th, 2012, 5:46 pm
by lerea3
Well, I got a 48 pilot today so I put her in. I also raised the clip to the top of the needle. It doesn't smoke like Adam's Manitoba mosquito fogger anymore, but the fricken plastic idle screw broke in 3 places :evil: The bike would just barely idle so I tried to give the screw one more turn and snap!!! Guess I'm waiting now.

Posted: March 19th, 2012, 7:33 pm
by AlisoBob
AlisoBob wrote:Snip off a few turns of the spring, to get the idle speed screw in deeper.
AlisoBob wrote:The way to adjust it is to open the throttle, turn the screw, and close the throttle.


Never heard of anyone snapping the screw off, thats a new one.

Posted: March 19th, 2012, 7:44 pm
by lerea3
Did both those things. The head broke off and the tip broke and is now stuck inside. I just had the whole ass end of the bike off to take the carb out. Now I have to do it all again. I just hope once the slide is out I can get the plastic tip out. :cry:

Thanks for the help so far!

Posted: March 21st, 2012, 8:23 pm
by lerea3
Bob, quick question, long or short zip Ty screw?

Posted: March 21st, 2012, 8:39 pm
by lerea3
I just tried ordering the short one and it said they can't ship to my address??? I guess I will have the call them.

Posted: March 21st, 2012, 9:18 pm
by AlisoBob
lerea3 wrote:Bob, quick question, long or short zip Ty screw?
The "Short" version is the one screwed into the carb in the photo.

The "Long" one is the one pictured loose.

I got the "Long" as its easier to find with gloves on.

Posted: March 21st, 2012, 9:40 pm
by lerea3
Thanks Bob. I managaged to get the broken plastic screw out and went to a local bike scrap yard, I found a brass throttle screw from an old bing Italian carb that fit perfect but my bike will still not idle. I don't think it's long enough. I will be ordering the screw that you gave me the part number for but just thought I would try the local picker first.

Thanks again for the help

Les.

Posted: March 22nd, 2012, 12:48 am
by johnnytheswede
Just for your information. The needle you are using is 3 numbers too short compared to one with the standard length, but i guess you know that now. The needle length of the DDJ at 1st clip is the same position as if you had a standard neele in 4th clip. Your needle is 3 numbers too short and about 3 numbers too fat. It won't help much right now if you have a leaner pilot as the needle messes everything up. Wait for your DGL and DGM needles=)! I guess DGM will be good in 3rd.

Johnny.

Posted: April 29th, 2012, 5:10 pm
by lerea3
Finally got a chance to ride today. With a 42 pilot, air screw 1.5 out, 170 main and a DGM needle in the 3rd position she seems to pull pretty hard. Starts with choke on second kick. I haven't checked the plug yet. Thanks to everyone for the help. One thing is the idle screw feel out on me, luckly the screw got hung up in the breather tubes so I didn't loose it, just the spring. What could I put on the threads so it doesn't happen again? Lock tite??

Posted: April 29th, 2012, 11:50 pm
by johnnytheswede
Nice:=)! Glad you start to get everything sorted! I use the DGM myself now. Sealevel and around 10-15 degrees celsius, 180 main, Zip-Ty airscrew, nr6 slide

Johnny

Posted: April 30th, 2012, 4:52 pm
by lerea3
Thanks Johnny! The needle you suggested worked great. How can I keep the idle screw from falling out?