Keihin PWK 30 Carb

[Cravin01]

I'm glad to hear I'm not off my rocker , I've been contemplating a larger carb even before I received the bike. The power jet seems like a good option along with a upscaling.

[Megadan]

Originally Posted by Ariel Red Hunter

Megadan, remember that Keihin carbs are described by the diameter of the air cleaner side while Mikuni's are described by the venturi diameter. a VM 28 is equivalent to a 32 mm Keihin. However, the Keihin shown in the link has a starting jet instead of a choke which should give improved performance above 3/4 throttle even with the 30mm model...ARH

These aren't traditional PWK's though, but knock off copies. They are literally a 30 or 32mm bore at the spigot, just like my VM30 is. I have all three if you want a side by side by side lol

[Megadan]

Originally Posted by Cravin01

I'm glad to hear I'm not off my rocker , I've been contemplating a larger carb even before I received the bike. The power jet seems like a good option along with a upscaling.

You cold give it a try. I would be interested in the results of a 30mm bore carb on an unported CG250 head.

That is something to keep in mind with Jerry's experiences on this carb, his head has been ported and decked.

[JerryHawk250]

If you look at the pz30 at the flanges end it measures 30mm but tapers down towards the slide. So technically it's not 30mm all the way through. Stock intake manifold is only 28mm at the head. Pwk30 is 30mm all the way through and the intake adapter is 30mm at the head. I did check that the head and manifold are port matched.

[RogerWFarrier]

The TT 250 has a Keima version of a Keihin carb and it was very easy to rejet and tune.

[JerryHawk250]

Originally Posted by RogerWFarrier

The TT 250 has a Keima version of a Keihin carb and it was very easy to rejet and tune.

is the idle mixture screw on the side? I thought it was on the bottom like the pz30.

[RogerWFarrier]

Originally Posted by JerryHawk250

is the idle mixture screw on the side? I thought it was on the bottom like the pz30.

Idle screw is on the side. It is a different model but it is a Keima and uses standard Keihin jets. https://www.cscmotorcycles.com/Articles.asp?ID=294

[Megadan]

Originally Posted by RogerWFarrier

Idle screw is on the side. It is a different model but it is a Keima and uses standard Keihin jets. https://www.cscmotorcycles.com/Articles.asp?ID=294

That is the idle speed screw, aka curb idle. He is talking about the idle mixture screw. That is located on the bottom of the carb, back side of the bowl between the two bowl screws.

[RogerWFarrier]

Originally Posted by Megadan

That is the idle speed screw, aka curb idle. He is talking about the idle mixture screw. That is located on the bottom of the carb, back side of the bowl between the two bowl screws.

Yes the screw that is shielded by an impossible to remove domed brass plug. I tried to drill it I tried to use a punch and nothing would budge it so the idle speed mixture stayed stock and I just adjusted the needle and changed the main to a 115 and left it at that.

[Weldangrind]

Lifanda requires a different bend at the intake tube, unless I ditch the battery box location. Jerry and Dan, are you aware of a bend that pitches the carb to the other side?

[Megadan]

I am fairly sure that I saw some that angled the other direction in my searches, but I would have to look around again to be sure.

[JerryHawk250]

Yes Weld, I've ran across some while searching. I'll look through my search history and see if I can find them.

[Cravin01]

Well I cant seem to be able to decide if this is worth my while, I read that a 4 stroke doesn't need a power jet but it never said it wouldn't give a improvement if used.

As always Dan threw in some valuable info about the carb and I will not be decking my head but I could polish the exhaust port myself, so I thought maybe I should look at the Keihin PWK28 ...But I'm not positive going to a power jet and a slide valve will give the desired improvement over the butterfly valve in the PZ30.

Opinions please!

[JerryHawk250]

Originally Posted by JerryHawk250

Yes Weld, I've ran across some while searching. I'll look through my search history and see if I can find them.

Okay Weld, I did some searching. Most of the ones I ran across were for a spigot mount carb. The one I did find for flange mount would be too small. 26mm. What kind of freak of nature you got? lol.

[Megadan]

Originally Posted by JerryHawk250

Okay Weld, I did some searching. Most of the ones I ran across were for a spigot mount carb. The one I did find for flange mount would be too small. 26mm. What kind of freak of nature you got? lol.

Yep, same result on my part. If you want a spigot mount carb, you are covered. Flange mount, not so much. I swear at one time I saw some 30mm flange mounts, but now I can't find them.