RB questions in general!

Questions and Answers about the best carb and Head mods available for the KDX.
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Indawoods
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Post by Indawoods »

Thinking... while I'm at it.... Should I go ahead and send my head in and get it modded? Anyone done this on a non-ported KDX? *** I WANT TO USE PUMP GAS *** I had to make that clear... :grin:

*Of course I am getting the new AS when I get the carb done*
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Post by canyncarvr »

Send everything in! Send in the air out of the tire!!

I have not used it on a non-ported engine. It DID run better with Ron's head work than it did in stock form after an FRP port job....and detonation was the problem!

Go figure! More compression, less detonation! Must be a squish thing.

Re; Air screw. Of course! Ask him to get the TORS off'a there, too!!

oops...wrong forum! :eek: That'sa Banshee thing....

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Post by Indawoods »

RBD...Where are you???? :cry:

Gee CC.... didn't think you'd own a couch! :lol:
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Post by RBD »

Indawoods,

The head mod for the 200's work just fine with pump gas, it will help with engine temps, better snap and will give a little and I say a little better gas milage.

Note, on the 200 head mod it is more a squish band change and a very little compression increase. On the 220's it is both a squish band change and more of a compression change as they are week in that department :neutral:
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Post by Indawoods »

Ohhhh I can always use better gas mileage! Snap is good too.... never had a problem with temps...but you never know as I explore different terrain all the time. I'll try to get them off to ya in the next week or so, always so much going on... :neutral: Thanks Ron...
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"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
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Post by m0rie »

Hey RBD is the Head Mod do-able on the E series KDX's (89-94) as well? If so does it have the same benefits as the H series (95-05) 200's?

-Maurice
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Post by RBD »

m0rie,

Yes it does :wink:
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Post by m0rie »

Ron,

Another question if I may. Not sure if you've looked at this but can you replace/rework the float needle seat on the PWK carbs? It doesn't show up in the parts manual as a replaceable item. My PWK pees like crazy and as far as I can tell the float is set correctly and the float needle appears the be okay. Since its most likely the original needle i'll replace it first to see if that cures it but i'd like to have a plan B if that doesn't work out. I've tried lightly burnishing the needle seat with some wet/dry sandpaper as that has been noted to help cure this problem before.

-Maurice
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Post by RBD »

m0rie,

You are right about the float seat not being replicable. Seeing how you have already tried burnishing the seat (hopefully you used very fine paper and it was done lightly) I think you should get a new float needle.

It is sometimes hard to see a potential problem with rubber tip, all it takes it a small cut or indentation, it could also be getting to hard. The rubber tip should be semi soft.

If you can see (use a magnifying glass) a indent in the tip where the seat makes contact, this could be a problem too.

I have never seen a seat that couldn't be cleaned up and be a problem unless it has been etched by water or salts.

Try the new float needle first, if that doesn't do the trick and your float level is set properly, I do have another trick to try on the seat, but it takes some good skills.

Ron
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Post by KDXGarage »

MY TURN! MY TURN! :-)

Hi, Ron. Since we are talking carbs, are YOU able to convert a standard PWK35 from left sided to right sided? I know you are familiar with the 1989 - 2005 standard PWK35, with the idle screw, choke knob and air screw on the left side of the carb. You may not be familiar with the 1988 KDX200 carb. On the 1988 KDX200 (last air cooled model), the airbox covers the left side fo the carb and it has a PWK35 with the screws and knob on the right side of the carb. Would you be able to convert a standard, left side PWK35 so that the idle screw and air screw would be on the right side? The choke knob has about $75 worth of OEM parts that are a lever and other parts, so that the choke assembly is still on the left side, but is adjustable from the right. One pushes down on the lever so that the assembly rides up, as if though the left side know was pulled upward.

Besides me wanting to know. another member here has a 1988 KDX200 that apparently a previous owner put a PE or PJ carb on, and I am trying to help him out.

Thanks a lot,
Jason
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Post by fuzzy »

RBD, thank you for being a part of this forum!!! :supz:

I'm sure guys like RB & EG would agree w/ this.....Almost ANY stock OEM 2T head has room for improvement, even w/ pump gas. It seems RB has mastered the KDX head so no worries about not getting what you pay for, or even worse getting a degredation in performance.

I've got to get my KDX 35mm out to you. I want to use it on my WR, and have gotten it close enough w/ jetting to ride but it still needs serious help(slide to rich, etc). Every PWK should be treated w/ your mod, but this one will be a little different then the same ole same ole...
'91 KDX 200 Project $300 KDX
'95 KDX 200 Project $600 KDX
'94 WR 250 Always a project
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Post by canyncarvr »

Leftsy-rightsy?

Good grief. That sounds like a nightmare!! If it is 'possible' it would also likely cost about 10X what it would to call Keihin and have them retool to MAKE the oem carb. Well..ok...a slight exaggeration.

Well...maybe not. Note the hassle to get the choke to work..and that's just added hardware on the OUTside.

I suppose the chances of getting the correct carb for that application is an impossibility?

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Post by skipro3 »

As a user of a reshaped KDX220 head done by Ron, I'll throw in my 2 cents:
Ron set mine up for race gas AND higher altitude. It works great. I have run from sea level to 9,000+ feet with out any issues with the head. I do not have a ported cylinder. It is stock. At the time, I also bought a RB modded Air Stryker carb from Ron. The only downside to the set-up is that the bike takes more poop to kick over and usually 3 kicks (hot or cold) to poke it into life. I've tried things to get that back to the single half hearted kick to start like it used to be, but she isn't a docile pony anymore. As a thouroghbred the girl wants to be stroked good and firm, more than once, before lighting off. That's not a problem unless you are really tired, like, 4th attempt at a steep hill you keep looping out on. THen kicking that thing is work. The extra compression is definately felt when kicking over as well.
Glad to see Ron here to help us all out. Thanks Ron.

Reversing the carb:
Just stick it on backwards. Then the controls are on the left side. Reroute the air flow with some old International Harvester radiator hose, (1953 was a good year for long hoses) and you are set!
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Post by RBD »

Hi Jason,

It sounds like you have the choke problem solved. The only other thing that can be changed is the idle screw. The carb can be drilled and tapped on the right side for the idle screw and the existing idle hole would need to be plugged (you would need a 5 X 0.8 panhead screw for that)

As for the mixture screw...... well your just out of luck on that one, or should I say it can't be done (the main body casting won't allow it)

On a second thought, I think skipro3 has the right idea, just turn the carb around :rolleyes:

Ron
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Post by KDXGarage »

Hello. Thank you very much for the information. I will pass it along, as well as keep it in mind.

It sounds like one would be best off to learn how to pull the choke knob from the other side and find a happy medium on the air screw and idle screw and leave it there. It is a whole lot easier to take an airbox off a C model (1986 - 1988) vs. a liquid cooled model, so I guees people could pull the airbox off, adjust and put the airbox back on (would take less than 5 minutes). It's not quick, but it is cheap. :-)

canyncarvr, a new OEM '88 KDX200 carburetor is $282.89 shipped from ronayers.com. I was curious as to how much it would be to convert my "1991 KDX200 carb that I got off eBay for $30" standard PWK35 that is already in the garage. I would like to see how the PWK35 would work on my '87. It is one of those "on the list" modifications. The Keihin PWK35 has more adjustability/common knowledge available than the stock Mikuni VM34SS (no air screw, for example).
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Post by canyncarvr »

I knew oem was a Mikuni. Actually wrote a reply regarding not being able to put the idle screw on the other side because the Mikuni slide has a slot the idle screw abuts. The slide doesn't have that slot on both sides.

..but then I realized you weren't talking about a Mikuni.....so I didn't say it. ;)

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Post by farmerj »

Note, on the 200 head mod it is more a squish band change and a very little compression increase. On the 220's it is both a squish band change and more of a compression change as they are week in that department
The only downside to the set-up is that the bike takes more poop to kick over and usually 3 kicks (hot or cold) to poke it into life
Ron set mine up for race gas AND higher altitude. It works great.
Given the above...
Will the RBD head mod create the same "harder starting situation" on an un-ported 200?

I'm thinking that "race gas" and the higher compression change on the 220 contribute to Skipro's problem, and that if I go with pump gas on my 200 the "problem" may not be as noticeable.

...Or should I plan on doing more leg workouts at the gym???!
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Post by skipro3 »

First, let me make it clear the kicking and starting is not so much a problem as it is a change. The KDX in stock form has a reputation of being one of the easiest bikes to start now or ever for that matter. The mods to my KDX make starting more like a typical MX bike. Not bad but more work than stock to be sure. Compared to a 4 stroke, it's still a piece of cake to start.
The change in starting ease definately came when I changed out the carb and head. (Performed at the same time so I can't say for sure one or the other is the leading cause.)
I've run race gas since day one and that is not the cause. Left over 2-stroke mix that I use in my chainsaws and leaf blower make them more difficult to start though.
For the average guy (I'm not, I've several leg and ankle injuries on the kickin' leg) I really don't see this as an issue. If it were, I would have Ron reshape my head back more to stock and adjust my jetting for cold start ease. For now, I practice not falling down and needing to relight the pilot so often!
Jerry

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Post by m0rie »

skipro3 wrote: For now, I practice not falling down and needing to relight the pilot so often!
Amen to that brother!
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Post by canyncarvr »

On a 200...but ported (not the exhaust port)

I can feel the difference. Not much..but there is some.

It didn't change the starting characteristics in that one kick lights it. You could argue feebly that a 1/2 hearted half fast kick would probably start it before...now you probably need more than a couple clicks on the ratchet to get it started.

In other words.........don't worry about it! Not at all a big deal.

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