Air Striker Carb

[Houndog]

Originally posted by Zerotact
I too have thought about the rb carb mod, but have found some pwk airstriker carbs in 36, and 38mm for the price of the rb carb mod. But I think $500 in parts will make a lot off difrenece, with a bigger carb, and new pipe. But due to shattered stock pistons, I'd avoid running a pipe with the stock piston.
http://www.pro-flo.com/proflo_keihin_flat_slide_carbs.htm#PWK AIR STRIKERS

This brings up a good point Zerotact, I see the enduro version of the 200 KTM and Gas Gas run a 38mm carb. (KTM EXC200 PWK 38AG, Gas Gas EC 200DE PWK 38).

Does this suggest that the Air Striker 38mm might be a good choice for a KDX 200, or would the RB mod be more beneficial than a new 35mm Air Striker? Has anyone tried a 38mm carb on a KDX 200 or 220?

 

[jaguar]

I think the carb mod would better suit woods riders, and the 38mm carb suit motocrossers.

 

[Zerotact]

but you can also get a 35mm air stiker carb for about the same price as the carb mod... I think a 38mm carb is a bit large, but would definately help the kdx 220 get some upper end, which it lacks in stock form.

It's basically the fact that you can buy a whole new carb for the cost of the carb mod...

 

[Houndog]

The 38mm would take some modification/innovation to make it fit too. Back to the 35mm AS, is it a worthwhile replacement for a worn 35mm PWK? Has anyone tried a 35mm AS without the RB mod?

 

[canyncarvr]

Why not get the AS carb with the RB mod?

No, I haven't used an airstryker without the modification, but there isn't anything in the 4-vent carb that will accomplish what the modification does.....seems an apples and oranges thing to me.

So...get 'em both!

 

[Houndog]

Originally posted by canyncarvr
Why not get the AS carb with the RB mod? 

Because I don't have your money :whiner:

If getting both doubles the cost, then I might have to look at the EG 225 with porting instead. This is how it's supposed to work, figure you are going to do an inexpensive mod and end up spending $800 OR find out that the old KDX is just fine and treat it to a tank of fresh fuel... I bet my wife votes for the new fuel :laugh:

 

[Zerotact]

I don't know all the details, but I would think that the As carb is slightly diffrent in design than the standard pwk, and performing the rb mod on an AS carb, may defeat the purpose of ponying up the extra dough for the rb mod. The 38 mm cab is larger, and the throats are 4mm bigger in diameter... So the 38mm might not work too well. But the 35mm AS carb seems like a good option for me and my 220 since I have a 33mm carb stock...

 

[pvxr400]

Go with the 35mm Air Striker and give us your feeback. I'd like to hear how it perform on a 220.


Thanks,

Patrick

 

[davidg]

I don't know what the 35mm AS carb goes for by itself. Though, $320 w/shipping for a RB modifeid AS carb was the best money I put into my bike(performance wise). I love it on my 220! I have the woods pipe on with it and I can now go toe to toe with my buddies 2003 cr 125 on the top end. Of course I always had more bottom end.

 

[Jim Crenca]

I just talked to Sudco about Air Styker carbs the other day; their thought was that it did have better response than a stock PWK, and that if you needed bigger than 35 mm, you should have it bored as no easy way to fit 38mm to airboots or between frame members on some years.

 

[BRush]

Comparing the air striker carb and the RB mod is comparing apples to oranges. A 38mm carb, air striker or otherwise on a KDX would will just trade off low end performance for top end. Overly large carbs have a negative effect on low end performance. It's a trade-off. That's why trials bikes have smaller carbs than motocrossers and why the 220 KDX has a 33mm carb while the 200 has a 35mm. The RB mod attempts to mitigate that trade-off. It does this (primarily) by installing a divider plate which allows the modified PWK to act as sort of the carburation equivalent of a bifocal lens. At low throttle openings, the area of the carb bore is effectively reduced. This keeps the fuel charge moving faster and improves low end response. When you whack the throttle full open, the whole area is again available to allow the motor to rev out. When jetted properly, it works very well.

 

[Eddiet]

I have been running a 35 air stryker for my 01 220 for a year now. This is a great investment for the 220. With a rev pipe, reeds, air box mod, and the air stryker, my 220 is perfect for enduros now. On the straight aways, the big four strokes do pull away from me a little, but when it gets tight, this 220 works like a champ. The needle and slide that comes with the 35 carb from SUDCO is way too rich. I took the needle and slide from my 33 carb put it in the 35 carb, started with the modified KDX 200 jetting specs and kept making minor changes till I got it perfect. The rb mod scared me with all the jetting issues they go through. Other than minor adjustments during the year, I have not had any troubles with the air stryker.

 

[BRush]

Originally posted by Eddiet
The rb mod scared me with all the jetting issues they go through.

The jetting issues with the RB are way overblown. One you dial it in - and there is plenty of info on this board to help you do that - you won't need to touch it again unless you enjoy tinkering.

 

[canyncarvr]

'..and performing the rb mod on an AS carb, may defeat the purpose of ponying up the extra dough for the rb mod.'

I must admit I don't understand what this says......:think:..but if it says the combination of the two (airstryker and the RB mod) is some sort of bad thing, well, that would be way wrong.

'..with all the jetting issues they go through.'

I'm batting 1.000 so far, cuz I don't understand this, either. I didn't even know I had 'jetting issues'!! :(

Indeed, there was a learning curve to the RB carb. But the work is all done, now!

How many kdx'ers you think were running a dek/cek needle before ron came along? From the input of this board, I'd say not very many (or none).

 

[Zerotact]

Ok, i rthink we can take this convo to a close, as Cd has chimed in on another forum, stating that the kdx carb is an airstriker carb essentially.

 

[shr]

Yes it is an Air Striker in part, but it does not have the two air foils leading up to the main jet nozzle and it does not have the quad vent float bowl system.

The only thing the KDX carb has in common to the Air Striker is it uses the same jet block and slide.

 

[canyncarvr]

re:'Ok, i rthink we can take this convo to a close, as Cd has chimed in on another forum, stating that the kdx carb is an airstriker carb essentially.'

Essentially? Does that mean they both began life as a bucket of bauxite? ;)

Yeah. I guess a 48/160/R1173K-3/#5TV carb is 'essentially' the same as a 40/152/DEK-4/#7TV, too.

Well, except for where they are completely different they are essentially the same.

The comment was taken out of context, misconstrued or misunderstood.

While the construction of the two carbs is similar (read: 'essentially the same') they certainly do not act/work/respond the same way.

You could say a 220 carb was 'essentially the same' as a 200 carb, too.


...sorry. Couldn't resist. Well, didn't resist anyway.....guess you might say I have zero tact?



Cheers!

Oh...and while the slides interchange between the two (airstryker and the kdx pwk), they are machined a bit differently. Another example you could use: 'SHR says the slides are exactly the same.' Well...no, he didn't say that. AND just because they use the same jet block doesn't mean they're mounted in the same place!.

So, we understand how 'essentially the same' can be tweaked?

 

[Eddiet]

We are all trying to achieve the same goal, to get the best performance out of our KDX's as possible. There are just differnet ways to do it. The concept behind the air stryker and rb carb are simular. I was able to get a new 35 AS for $150, plus I still have my 33 carb. With me and two boys racing, I need to get the most bang for the bucks I can. The mods I have are 35 AS carb, shaved head for increased compression, rev pipe, reeds, and air box mod. This bike really rips now and is a good enduro bike. I spoke with Fredette at the Alligator Enduro in Daytona, he says the only thing I am missing is the port and polish job. I guess thats the next money to be spent.

 

[canyncarvr]

Yanno...I just reset a whole bunch of attempting to make sense of:

'The concept behind the air stryker and rb carb are simular'

Yep. They both mix air with fuel.

Come to think of it, they are exactly the same!

Other than that, they are completely different!

But....what do I know. I've run the oem pwk, an rb-modded pwk and an rb-modded airstryker.

I really have no opinion on the matter.........
;)


Now then....how do I get this 4778 holley strapped on my scooter..cuz it's 'simular', too!

Cheers!

 

[Houndog]

Originally posted by canyncarvr
Now then....how do I get this 4778 holley strapped on my scooter..cuz it's 'simular', too!

LOL,

That might be hard to jet, were you looking for more top end? ;) 

 

[canyncarvr]

Top end indeed!

Considering the volumetric efficiency of a 198cc displacement 2-stroke, how fast you figger it would have to spin to swallow 750cfm?

I've got the math for that somewheres................

I wonder if I'll get enough vacuum out of it to run my power brake booster:think:

 

[Lizard Lips]

The KDX 220 comes from the factory with a 33mm carb to add to low speed velocity (torque). The reason I went with RB conversion on mine is because (and correct me if I'm wrong here) by boring it to 36mm and installing the divider plate you new effectivley have a variable geometry veturi. The plate runs all the way to the slide and contours around it. The upper half of the throat is blocked off up to half throttle. This gives you a 28mm carb up to half throttle becuase the slide blocks the upper half up to that point. The pilot jet size drops because of the increase in velocity. So with the Mod you get a gain in efficiency over the stock 33mm PWK for lowspeed torque and a gain in high end as well when you open it up beyond the divder plate and use all 36mm. Best of both worlds the way I see it.

 

[Wolf]

If Lizard is right, thank you soooo much. I finally get it and it seems to make sense.
If Lizard is wrong..."Asta La Vista, Baby" :moon:

 

[G. Gearloose]

Well, allmost. The pilot drops in size mostly due to using a needle with a smaller diameter straight section (read: richer), but thats pretty accurate.