Keihin PWK 30 Carb

[Megadan]

Originally Posted by JerryHawk250

Bigger is not always better unless you are going with larger cc engine.

Or revving the engine out higher, which usually means a powerband shift.

For the sake of curiosity I do have a 32mm carb, and CCW ran a 32mm carb on their land speed record bike as well, but that bike also had a custom cam profile, high compression, and obviously head porting that also revved out past 9000rpm. For road use, a 30mm smooth bore carb is plenty big enough for a ported head on an otherwise stock engine. My bike happily winds out already with the pumper carb, which is just like the stock unit, but it feels a little restricted up top. Once I get done with some in depth maintenance on my VFR the Hawk is getting switched over to the PWK.

[Kivi]

There is a PWK with just few hoses and a PWK with several hoses around it and several connections for hoses. I see these are vent hoses. Whats the difference with all these hoses?!

[JerryHawk250]

Originally Posted by Kivi

There is a PWK with just few hoses and a PWK with several hoses around it and several connections for hoses. I see these are vent hoses. Whats the difference with all these hoses?!

Some like mine has the power jet and some don't.

[Kivi]

Pwk can have different versions:
Can be with or without Air Striker which directs air entering from air filter to main nozzle for improved signal and throttle response. Most of carbs but there are versions with this and are usually more expensive than the version without. Also, the slider itself is cut with an angle, thus additionally directing air toward the jets. This gives more precision in carb control, or say it, air flow control up to 1/4 throttle. I think that only Air Striker versions have this angled slider, while other versions have really flat slider.
Air Striker versions available from 35mm and up.

They can/might not have 4 air vents, which are routed by 4 hoses to a 2 different locations, usually one location is up high on the bike. One vent is for fuel overflow. This vents eliminate post jump bogging. This should be characteristic for a racing trial bike. For most of enduro riders this is not important and unnecesary, as long as bike does not fall to the ground or worse. It requires more maintenance and can lead to faster carb clogging.

They can be with or without power jets, which was discussed in this thread.
They can be with screw slide cap or with 2 bolts cap.

On sales sites you can find cheaper versions which use different jets, while there are versions that use jets same as keihin.

[Kivi]

On sales sites 30mm pwk is specified for upto 150cc. At the same time, for a 200cc engine, with 27-28mm intake, and 27-28mm org carb, 30mm carb is already max size.
So, maybe the circuits on these pwk clones are somewhat different, or less efficient, so that they specify the 30mm pwk for 100-150ccm. Im puzzled.

[Megadan]

Originally Posted by Kivi

On sales sites 30mm pwk is specified for upto 150cc. At the same time, for a 200cc engine, with 27-28mm intake, and 27-28mm org carb, 30mm carb is already max size.
So, maybe the circuits on these pwk clones are somewhat different, or less efficient, so that they specify the 30mm pwk for 100-150ccm. Im puzzled.

Those are 2 stroke sizes for racing applications.

[Kivi]

Megadan, thanks! Can I take pwk 28mm, then? Im thinking, my pushrod 200cc Zong does not like high RPM, it's loud and it is not confortable. I really like the low RPMs and middle. I rarely drive it in high RPM (but I dont have tacho, though), but I ocassionally drive WOT, but not high RPM.So, was thinking getting smaller carb, which should be better for low RPM for this pushrod....

[Megadan]

A 28mm would work ok on a 200cc, though I couldn't tell you how it would affect the power curve. PWKs tend to have better throttle response then a round slide and it will likely give a.strong mid range.

[The_DJ_Remixer]

Hey fellas,


newb question...
Ive bought the aftermarket exhaust, plan to do the airbox mod, but I do not have any interest in messing with the head. I see you guys posted several links to carbs...what carb should I use if I dont want to change the rubber tube from airbox and also dont want to change the inlet rubber. (Im trying not to order from Alibaba I dont want to wait 30 days for the parts)...any info would be greatly appreciated!

[Megadan]

I tried fitting my PWK today since the bike is down for the front wheel issue. I don't know if there i just a wild tolerance issue with the intakes, or they just send out random parts, but mine doesn't fit by a mile. The carb literally will not go into the intake without hitting the center tube at the back of the frame.
I don't feel like playing $10 roulette to keep ordering intakes for them to work, but it sure would be nice to find a reliable source of intakes that actually fit.

[Megadan]

Originally Posted by The_DJ_Remixer

Hey fellas,


newb question...
Ive bought the aftermarket exhaust, plan to do the airbox mod, but I do not have any interest in messing with the head. I see you guys posted several links to carbs...what carb should I use if I dont want to change the rubber tube from airbox and also dont want to change the inlet rubber. (Im trying not to order from Alibaba I dont want to wait 30 days for the parts)...any info would be greatly appreciated!

Well. the carburetor in question on this thread is instantly not for you if you want to keep the stock intake setup.

Your options are.

1. Keep and tune the stock carb. A member on here by the name of NzBrakeLathes sells a pretty decent "retune" kit for the stock carbs that comes with main jets, an adjustable needle, a .45mm micro dill bit for the pilot jet, and new screws for the bowl for about $20. This is the cheapest option.

2. Do the Mikuni clone "30mm" VM26 (usually around $30ish) and buy genuine Mikuni main and pilot jets (another $20-30). Join the ranks of hundreds and have endless tuning advice on tap.

3. Upgrade to a PZ30B "Pumper" style carb like the one I am using. You can get the carb with the double ended cable and a quick turn throttle housing for around $30-35. Much like the Mikuni Clone, you will likely need to buy some jets to get it dialed in. The downside is the 20-30 day wait for it to arrive as there are no US based sources that I can find. Even the ones listed on ebay and Amazon ship from China. Go this route and be part of an elite group of 4 or 5 guys on here that have one lol.

In my opinion, of the three "stock" style carburetors, the accelerator pump carb is going to deliver the best on terms of "bang for the buck" entirely due to the accelerator pump. Unlike the Mikuni clone or the stock carb, it will deliver nearly instant throttle response, and makes the bike feel much more powerful and alive. It's what I currently have installed on my Hawk with a ported head, and it is a complete blast to ride.

The main advantage of the Mikuni clone is that there are a ton of people here, myself included, that had or still have this carb, so the tuning info is abundant. The throttle response is, at least in my opinion, just a bit better than the stock carb thanks to the intake and carb bore lining up perfectly. It's a subtle difference and many people likely wont notice it, but I did.

Tuning the stock carb with the kit mentioned is the most budget friendly route. It gives you all of the adjustability with the exception of the pilot jet being a unique piece that you can't buy other sizes for. The only option you have is to drill the pilot out with the included drill bit if you find the stock pilot too small for your application.

[NzBrakelathes]

Here’s the kit I sell / I listed genuinely the common shipping times as I’ve sent 60 or more kits and yes it can be as fast as 8 days mostly 14-18 and some nearly 30.
The speed is pot luck passing USA customs it seems.
https://rover.ebay.com/rover/0/0/0?m...2F303077495104
Also I can supply a PZ30 pumper and all the kit parts suit the new carb upgrade should you choose to do so, starting with stock you can tune it good and later upgrade with the pumper n use all the jets and I will include more in between sizes with the carb.
IMO it’s a good logical pathway from learning to an upgrade should ppl need or want later and the parts interchange recycle reuse so environmentally and pocket friendly?!
Have a look at the list of what’s included etc
Regardless of what you choose, make it a good choice for your needs wants and NO this isn’t the only way to solve some issue but it’s a good option and less waste imo

[Megadan]

So, back on topic. I am giving the angled carb intake/adapter one more try from a different seller. It LOOKS like it should work, but we will see.

I also decided to give one of these a try. I have a feeling it may not work, but for 4 bucks, it is worth a shot. https://www.aliexpress.com/item/Alco...65154c4dTkG9De

I might have to do a little port matching to the head with it, but otherwise the only potential issues I see are. Possibly not enough clearance at the frame/fuel tank since the carb will sit higher and not enough room for a filter/intake setup at the frame. The one advantage would be a straight shot at the intake port. The angle of the carb may require some float height adjustment and/or slight changes in jet sizing due to the angle of the carb, but that will have to be seen.

I have about a 3 week wait to see if either one can work.

[NzBrakelathes]

Those are short but if you’re not fitting to stock air box it wouldn’t matter
I’ve seen many lengths to this style etc pretty common

[Megadan]

The quest continues. I came across this intake. https://item.taobao.com/item.htm?spm...ucket=2#detail

It's a bit longer and less angled down than the one you used Jerry, but as far as I can tell the CQR had the carb angled in the same direction as the Hawk (out to the right), so I am going to give this one a try. 3 bucks plus whatever shipping will be. Hopefully it works out because I am tired of not being able to use my PWK.