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Have the AS out @ 2 1/4 turns and it just rolls on fast, smooth & OH YEAH

You'll know its there when 3rd gear 1/4 throttle just pulls away stronger than you can believe when it should have stalled out.

what a great feeling! finding mine confused the heck out of me

You will come to know when it's 'on' and when it's 'not' real quick. Remember that a very small adjustment can make the difference.

k-ski..I don't recall you having an RB modified carb. Wasn't your carb bored by Fredette?

..don't see your bike listed in the profile section.....

canyncarvr wrote:You will come to know when it's 'on' and when it's 'not' real quick. Remember that a very small adjustment can make the difference.

k-ski..I don't recall you having an RB modified carb. Wasn't your carb bored by Fredette?

..don't see your bike listed in the profile section.....

yes it was bored by fredette, what is the difference between the two carb mods ,RB and Fredette. Ya! I should do my profile It would proubly help with all the stupid questions I ask. so speaking of Questions what is the real seat of the pants feel between the DEK and DEM needle ? as JD's chart shows only a small change around 1/8 throttle given the same base line jetting.

I rode in the mud sunday thick slippery 450 eating mud, it did load up a little as I never managed to get over 14 mph and had to keep it in the next higher gear to keep forward momentum. I did take a CRF 250 and yzf 450 thumpers to the cleaners , they had a hard time keeping the wheels on the ground. this is my first KDX and it was made for the ugly stuff.

RB is bored to 36, slide cut to #7 and a divider plate installed on the intake side to give you the best of the 33mm and the advantage of having it bored. He also modifies the pilot circuit so your air screw works very precisely.

With the #7 cut slide it allows you to use the CEK and DEK effectively.

What a world of difference this has made on my bike.... I feel like I am in control of my bikes behavor instead of being all over the place trying to get some results.

Copied from http://WWW.RB-DESIGNS.COM

Carburetor Modification for the 200 and 220 includes;

Boring carb to 36 mm (gives you a better top end)

Installing divider plate (gives that low end response, like a smaller carb)

Modify slide (do not forget to send your slide with your carb)

Install new needle (gives the carb that personality)

Change jets (if necessary)

Modify jet block (helps with the over all performance)

Modify low speed circuitry This part of the modification along with the other mods really brings the air mixture screw into play. With only very small adjustments, you can keep your bike running at its peak as you change altitude or with weather changes during your ride.

you all seem to have and like the RB mod, mine was done byFredette I dont know what he does except bore it out but I like it.

I've heard the argument 'for' a Fredette bore over an RB mod being the cost. The point is, the boring of the carb body alone is not what you get with Ron's modification.

Re: '..but I like it.'

It's hard to appreciate what you don't have...how would you know the difference?

I am aware of the time it took, machine shop time, seat (riding) time, dyno time to get to what we know as the 'RB carb'. I'll bet'cha anything you want that no such time, design, testing, and effort went into what Mr. Fredette does. I'm not discounting his carb boring jobs...I've never seen one, used one or known anyone that had one. I have had work done by Ron on more things than KDX carbs. He has excelled in everything he's ever done. I have had work done by Fredette that was/is less than stellar. My hunch is my main complaint is with a vendor Fredette used (US Chrome) more than FRP itself..but they (FRP) I think should have known better. There are some other problems, too.

Problems with RB-Designs work? Ha! Last I heard (well, rumour has it) hell has NOT frozen over. I don't think Ron is even capable of being part of any 'problem'.

Re: 'it did load up a little..'

I can tell you exactly the number of times my bike has 'loaded up' with a RB-Designs modified carb.

0

That's zero, nada, never.

k-ski: What needle are you running?

cc, I am running a DEM -2 with a 155 main 42 pilot airscrew 2 1/2 to 2 3/4 out no lid with no toil filter, there is a lot more info on what is and went into the RB carb mods and mine does look as if it was just bored out and not finished like I would expect it to. with the info at hand, if I did not buy the bike like its I would lean to having RB mod the carb because he does give detailed info on the modification to were their is none from Fredette. OH! that would be a loosing bet for me!

Good! At least you're off the 'B' needle! I've not tried a DEM with what would likely be the corresponding slide, a 5 or 6...but it sounds to be about right.

If it's on -2 because it's always been on -2, try -3 and -4 just for grins. I'd be curious if a DEM showed similar results as the DEK. If that turns out to be the case, you will be glad you tried the different clips!

That is curious about your air screw. I wouldn't have thought that would be so without pilot circuit modification. I've tried the SSS idea on unmodified carbs and different models/brands of modified carbs...it's not there.

BTW, what was confusing about it?

BTW, what was confusing about it?

what happened to the first one?

humidity @80% TEMP 91 DEGREES MAKES BREATHING HARD FOR THE BIKE I LIKE THE DEM ON THE -2 THERE IS NO REAL TWO STROKE HIT THE POWER IS SMOOTH AND ON THE PIPE FROM BOTTOM TO TOP. ON THE -3 IT DEVELOPS FOUR STROKE CONDITION 1/2 THROTTLE AND HITS HARD AFTER 3/4. THE CEM HAD MORE OF A TWO STROKE HIT. I LIKE THE SMOOTHNESS OF THE SET UP NOW ALSO RUNNING 13/49 GEARING 2ND GEAR TECH HILL CLIMBS LIKE A 4 STROKE, AND THE LAST FOUR STROKE I WAS ON WAS A 650 LOTS OF GRUNT, MY GOAL HAS BEEN TWO GET THE KDX TO RESPOND LIKE THE 650 AND IT DOES A FINE JOB NOW .I FIND MYSELF RUNNING A GEAR HIGHER.

The first one is for sissies.

sense all I know is that my carb has been bored,I cant help but wonder what difference the other mods that rb does would do, or undo? I haven't had much luck Getting a hold of Jeff. just the tinkering curiosity in me.

The person to find out is you! So...get your airstriker ordered and let us know!

Rumor had it that Mr. Fredette did not care for the RB carb. Dave Otteson (CanadianDave) sent him one to try out because he (Dave) was so happy with it. Reportedly, Mr. Fredette said, 'It's too picky to jet.'

As I recall (note disclaimer at the bottom of everything I say!), that was before JD's and fishhead's input into the carb that came 'round to 'C' and 'D' sloped needles. Heck..at one time testing on the modified carb included 'A' needles..which turned out to be just plain AWful!

Whatever Mr. Fredette's experience preceeded or not matters not a whit to me. I'm not one to jump on some bandwagon ('Mr. Fredette says THIS.....') because it's the chic thing to do. If the stuff don't work (if I don't like it), well...I don't like it! Obviously if it DOES work..then I'm a fan!

re: 'IT DEVELOPS FOUR STROKE CONDITION'

A 2-stroke bike that never four strokes is NOT happy.

...just to be argumentative.

Honestly. I think a brandy new RB-modified air striker should be on your short 'gotta have it' list. Let us know what you think!!