Which way should I go?

[skipro3]

I didn't want to hijack spivv39's thread on the 220 carb, well yes I did, but I figured I would get more replies if I didn't, so here is my very own thread and set of questions:
I'm finally desiding to let either Ron have a go at my carb or sell me the airstryker, but wanted to read up on it from his site and not bother him with answering a bunch of e-mails. But I guess I'll just have to bother him any way. In the meantime, I want to see if there are any recommendations of one over the other for a KDX220 looking for increased performance in the lower rpm range. CC hints that the AStryker is better and Wibby went with the bore job. I am planning on having Ron do the head rework as well. Running race gas VP C-12. Anyone out there have Ron modify the head and can report on it's performance? Anyone have an opinion for which way to go with the carb; bore or replace with AS? I'm planning on entering several enduros this season and looking for a way to pass all those C riders littering the hill climbs.
Current mods include: Airbox lid removed, VForce Reeds, Wiseco Piston, Gnarley Woods Pipe, FMF Turbo S/A, Flywheel Weight, 12 tooth CS gear.
As always, thanks for everyones input.

 

[KnoxKDX]

How do you like the flywheel weight--big difference?

 

[skipro3]

I love the flywheel weight. Very easy to install, it smooths out the power band so there are no hard hits. But most importantly, it keeps me from stalling the engine at low speeds and when I apply the rear brake on steep downhills. That extra weight keeps the piston moving when before, it would stall. Very helpful on hillclimbs or real tight manuvering when you just can't feather the clutch.

 

[m0rie]

In the meantime, I want to see if there are any recommendations of one over the other for a KDX220 looking for increased performance in the lower rpm range. CC hints that the AStryker is better and Wibby went with the bore job. I am planning on having Ron do the head rework as well.

All things being equal the AirStryker is the way to go. You get a new carb (with shiny new hoses) and you can keep your old carb to compare the RB-modified one to. Not mention that you've got no downtime while your waiting for the carb to get bored by Ron. Plus you can always sell the old one to recoup some of the cost of the carb bore.

-Maurice

 

[skipro3]

That's what I'm trying to determine: All things being equal. If they are equal then I will go with the Air Stryker. (If it isn't too much more cost wise.)

 

[Robcolo]

IF you live & ride in & around Tahoe --you're high altitude and the head mod is an absolute must. I believe the numbers are 3% loss in pressure / engine efficiency per 1000 ft. My head's been milled .028" and the lowest elevation the bike's ever seen is around 4000' with no detonation on 91 oct pump gas. I put the stock 33 carb on my mill table and bored it to [almost] 36mm. Bottom end is quite good -but not as good as my old KX 250 with an Eric Gorr low end cylinder job.

 

[skipro3]

Thanks Rob, good point.

 

[FLBusa]

Does anyone know what the AirStryker carb does that an RB modded carb does or doesn't?

I'm really curious as this will more than likely be my next mod.

I do like m0rie's thinking about having two carbs. :thumb:

 

[m0rie]

Does anyone know what the AirStryker carb does that an RB modded carb does or doesn't?

The Airstryker by itself doesn't do much more than a standard PWK. Its got better throttle response and from what i've read is a little easier to tune jetting-wise. A stock Airstryker isn't going to be as good as RB modded stock PWK. Likewise a RB modded Airstryker is going to be better than a RB modded stock PWK because of the extra throttle response and tuning that it brings to the table. If you've got the cash seems the Airstryker is the way to go. Get that little bit of extra performance above the reg PWK and an extra carb to boot. Otherwise just send the stock PWK to ron to have modded. Either way your going to be happy with the result I think. If your not i'll be first in line to take it off your hands :thumb:

-Maurice

 

[FLBusa]

Thanks Maurice,

I think shipping my carb off and getting the RB mod is the way to go for me. I've heard enough positive comments about the mod to feel confident about getting it done. Once I mod the bike it pretty much stays that way so I don't think I need an extra carb.

 

[wibby]

In case you are wondering about pricing

RB modified Airstryker $325 / including shipping

RB Carb Mod. $165 / including shipping



The Stealhy Flywheel Weight is really amazing!

My bike died on an uphill section Sunday, I immediately pulled in the clutch and the motor refired!

that was pretty cool! :thumb:

I don't know about it smoothing out the powerband though...

My bike will still hit plenty hard, depending on how I've got the a/s set :yeehaw:

 

[skipro3]

Smoothing the powerband for me means that it isn't herky jerky at low rpms anymore and the hit from mid to main is not as abrupt like an afterburner kicking in. I now have a much steadier pull from low to high rpm's. No suprises. Also very forgiving on stall situations by extending the powerband to a lower rpm range due to the flywheel momentum keeping the piston in motion.

 

[skipro3]

O.K. With income tax return on it's way, I've desided to get the ultimate and go with the airstryker carb, the race gas version of the head mill/squish band mod and the new and improved air screw. Total damage $390. Ron sounds very excited to do the head work for a race gas fueled KDX220. Now to get this timed right since I have 3 enduros between now and May 23rd. I'll update here when the parts are installed and provide a ride report on the overall performance changes.
In the meantime, has anyone had the gold valve installed in the REAR shock? If so, what do you think of it?

 

[m0rie]

O.K. With income tax return on it's way, I've desided to get the ultimate and go with the airstryker carb, the race gas version of the head mill/squish band mod and the new and improved air screw. Total damage $390. Ron sounds very excited to do the head work for a race gas fueled KDX220. Now to get this timed right since I have 3 enduros between now and May 23rd. I'll update here when the parts are installed and provide a ride report on the overall performance changes.
In the meantime, has anyone had the gold valve installed in the REAR shock? If so, what do you think of it?

The Airstryker combined with the head mod should really give your bike a kick in the pants. Certainly help at altitude as well.

-Maurice

 

[skipro3]

It's that kick in the pants that has me thinking now about the rear suspension. High speed compression is less than desireable on the rear. Front low speed compression is needing work too but isn't as objectionable as that rear is now or will be with extra power.

 

[canyncarvr]

An airstryker carb without the rb modification is a waste of time and money. Ron found that it was a big fat loser on the dyno when compared out of the box to a 'regular' pwk. It (the airstryker) lost a number of ponies as I recall.


I didn't look too much for verification of that, but I'm pretty sure about it........

An out-of-the-box airstryker won't fit on your kdx. You need to use (or buy another) top cap that has the radiused entry for the throttle cable.

Wibby had his cylinder head modified by ron. Ask him.

There is a whole lot more to head machining than raising compression. Read ron's write-up on his website about it.

The AS isn't a great big huge deal over an rb-modded oem pwk. If you're going to get SOMEthing done and $$ don't really matter, then why not get every advantage?

Wibby maybe don't care cuz he said he might buy my 200...and he thinks mebbe the airstryker will come with it?

I never said it would.......;) Sheesh..isn't an mx-suspended, wer dampened, steahly weighted, frp ported, just replated, DF reeded, just-rebuilt shock (house of horsepower), hydrosyn'd lubed, devol rodded, electrex lit, comes with two pipes bike ENUF??

 

[skipro3]

The Air Stryker will be modified by RB. Sorry, I thought that was a given and didn't mention it. I'm going with the AS because I like the idea of the jetting being more forgiving. When a ride can take me from 2500 ft to over 6500 in a day, I don't want to be stopping and swapping jets or living with a compramise.
I would never have even considered a head mill if Ron wasn't the one doing it. If anyone knows of reasons NOT to have it done, let me know your thoughts.
CC, it's never enough. And if your selling the KDX, then what's next in line for you to ride? Let me know how you like the reworked shock. I'm looking into getting mine rebuilt, revalved and could use some advise here.
Wibby, how's the head job? :laugh: :joke:

 

[wibby]

I fear 'Carvr's headed for the Punkin Room :eek:

Wibby, how's the head job?

Well, I'm sure it helped some....
But I'm always changing so many things all at once, I can never really tell what's making it go fast and what's not! :think:

 

[m0rie]

I fear 'Carvr's headed for the Punkin Room

Say its not so...Maybe he's just planning a sneak attack on the Pumpkin boys though...

Step 1 - Buy Pumpkin
Step 2 - Buy Green Plastics
Step 3...?

-Maurice

 

[skipro3]

He always had a punkin additude anyways. I was seriously considering it myself until I spent a little time on a 300 EXC. They need just as much to make 'em work the way you want as any other bike and always seem to demand an aggressive approach to riding without much forgiveness for the play around type of riding. Fine if you are young and fit, it wears me out.
As my friend Arnold has said, he'll be back.

 

[kdxtaz]

He always had a punkin additude anyways. I was seriously considering it myself until I spent a little time on a 300 EXC. They need just as much to make 'em work the way you want as any other bike and always seem to demand an aggressive approach to riding without much forgiveness for the play around type of riding. Fine if you are young and fit, it wears me out.
As my friend Arnold has said, he'll be back.

:thumb:

 

[89kdx200rdr]

wibby what weight flywheel are you running?

 

[wibby]

wibby what weight flywheel are you running?

I believe it's a 10 oz.

I fear 'Carvr's headed for the Punkin Room

It's even worse than I thought.....:ohmy:

I heard a rumor he's now looking at one of them RED bikes with a "BUTTON" :eek:


I need another BEER!

 

[acutemp]

Skipro3,
I run a gold valve in my KDX's shock, it is a pretty simple installation and is well worth the effort. The stock setup was really prone to deflecting out of line pretty easily and was a bit harsh for my liking. The stock shock piston is really not that bad, but it does need revalved at the very least to complement any fork work. I like doing my own work so the gold valves were good choice for me. If you have any questions on the install feel free to ask. Ron did the headwork on my bike and it set up for race gas. It definately added some exta bark to the bottom end.

CC,
My memory could be wrong on this one but I recall the stock 35mm AS carb was pretty close in top end to the modified 36mm carb it just wouldn't pull a load off of the bottom nearly as well.
--Dan

 

[skipro3]

Thanks for the feedback acutemp! My riding bud, Doug,a much better mechanic that I, tried to install the gold valves in his KX 500 forks. They even included a 30+ minute video, so we thought, hey, I can do this! Then we started taking things apart. No where did the video mention about taking the rebound stack apart or all the special tools needed to do so. The compression stack was all that the video discussed. We should have read the instructions closer. Luckily, there is a fanchise of sorts for this system and one was within an hours drive of the house. $140 later for labor and the boingers were complete and ready to run. On top of the origional gold valve cost of $140+ I might add. Well worth it though, according to Doug. Placed 7th? (I think) in his class at the Little Piglett Enduro last weekend.
So how difficult is it to change the rear shock to gold valve? What did it cost? Is it worth the price? How did you recharge the nitrogen? I have access to tanks of the stuff, BTW. I have the shop manuals and am a good enough mechanic to do all my own work but split cases, (never tried, so maybe? Na) and now rebuild rebound shim stacks on KX forks.
Also, where did you find the info on the AS top end V.S. modified 36mm carb?
89kdx200rdr: 10oz flywheel weight from steahly. (I know you asked Wibby and not me, but you get my input anyway for attempted hijack) I don't think it comes in any other size.
Wibby: I had a bad premonition that CC was going to a 4 Stroke but NOT red!!! Your his friend....time for an intervention.