E series RB upgrade

Questions and Answers about the best carb and Head mods available for the KDX.
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Friedom
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E series RB upgrade

Post by Friedom »

So my bike is running really well. Usually. Pulls hard almost the whole way through with an endless top end WOT that has scared me.
Except today it was humid, rainy and a little colder. Top end was a little bit puny, and the best throttle position was around 1/4 or less. Is this due to weather change? Am I too rich?
Which leads me to wondering about the RB carb options. $180 + to get my 24 year old carb modified, or $350 for a brand new striker or quad, and I could probably sell my old working one.
What say ye, mighty dx riders?

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SS109
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E series RB upgrade

Post by SS109 »

You're experiencing why a lot of people don't like carbs. Temp, humidity, elevation, and air pressure are constantly changing and therefore are always changing your ideal jetting.
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E series RB upgrade

Post by ohgood »

Friedom wrote:So my bike is running really well. Usually. Pulls hard almost the whole way through with an endless top end WOT that has scared me.
Except today it was humid, rainy and a little colder. Top end was a little bit puny, and the best throttle position was around 1/4 or less. Is this due to weather change? Am I too rich?
Which leads me to wondering about the RB carb options. $180 + to get my 24 year old carb modified, or $350 for a brand new striker or quad, and I could probably sell my old working one.
What say ye, mighty dx riders?

Fun Wheel Drive

i'm saying do both. worn out carbs SUCK and will drive you mad trying to nail down the jetting. if RB's mods are anything remotely close to what the difference is new vs old, then it's worth every stinking penny and then some. at the very least, get a new carb, i bought and pwk 35 and freaking love it. looooove it, vs the worn out pwk 33.

seriously, good carburation is WORTH it. whatever you do, holler at us and let us know what you find.
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Re: E series RB upgrade

Post by Tedh98 »

I wouldnt send your old carb to RB. Sell it and buy a new one.

If you really want to jet it and forget it, have you looked at the Lectron? I am not familiar with the E series, but I dont it will be a direct bolt on.
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Re: E series RB upgrade

Post by Friedom »

I realize temp., humidity, elevation all matter, but it was such a yuge difference for that ride. Maybe it's a 2 stroke thing, as my DR has worked fine with the same jetting here, up the mountains, down in Arivaca, in the Mojave, I only have to touch the fuel screw once in awhile to tweak it. Then again, I put a brand new carb on it.

I've heard a little about the lectrons, but not nearly the rave reviews that'd I've heard about RB'S work.
Air stryker or pwk35 then?

I'll probably get aftermarket reeds too - will they make it louder? Sure is noisy when it gets on the pipe. I'm grateful to have that extra gear so I can keep the rpms down to keep it quiet when I don't need the extra kick.

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E series RB upgrade

Post by SS109 »

2T's are more sensitive than 4T's. Just the way it is.

If I had a choice I would go with the Air stryker over the regular PWK. They are, supposedly, less sensitive to all the atmospheric variables. I've had several friends run the Lectron carbs and love them. They rave about them like we do about RB's carbs. However, mounting on some bikes can be a real pain as they are a longer carb.

Hmm, never heard anyone bring up how loud a bike is with certain reeds. I honestly don't know if it makes any difference sound wise.
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Re: E series RB upgrade

Post by Friedom »

SS109 wrote:2T's are more sensitive than 4T's. Just the way it is.

If I had a choice I would go with the Air stryker over the regular PWK. They are, supposedly, less sensitive to all the atmospheric variables. I've had several friends run the Lectron carbs and love them. They rave about them like we do about RB's carbs. However, mounting on some bikes can be a real pain as they are a longer carb.

Hmm, never heard anyone bring up how loud a bike is with certain reeds. I honestly don't know if it makes any difference sound wise.
Thanks. I don't see why different reeds would make it louder, but I've never had reeds before, so for me it's just theory.

I can see why you guys like these bikes. It was a whole new experience riding it, especially at speed. Much more nimble, and as I worked my way up in confidence it did whatever I asked of it. The suspension was a little harsh, but backed off a few clicks and it's a dream. Took a few jumps and the landings were so plush I wasn't sure when they actually happened. Maybe I can get out for a ride with you guys soon, SS. Haven't seen any Marana rides posted lately, though.

Anyone want to buy a working stock carb? :-P

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Re: E series RB upgrade

Post by jjavaman »

I got the carb and head mod done on mine last year. I am so happy with it, went from a stalling,blubbering piece of crap at low rpm's to a stump puller. Comes onto the pipe smooth, best $$ I've spent on the thing. I believe RB basically rebuilds the old carb to new condition when he performs his magic.
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Re: E series RB upgrade

Post by Friedom »

jjavaman wrote:I got the carb and head mod done on mine last year. I am so happy with it, went from a stalling,blubbering piece of crap at low rpm's to a stump puller. Comes onto the pipe smooth, best $$ I've spent on the thing. I believe RB basically rebuilds the old carb to new condition when he performs his magic.
Probably wouldn't fix slides and parts that wear.

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Re: E series RB upgrade

Post by jjavaman »

They replace all the worn o rings,modify the slide, etc. If there are any parts that are beyond service they replace it or let you know. It would be a little irresponsible on his part to do his mods and send out a worn out carb and he is not like that.
97-220 with a PC pipe. 2015- RB carb and head mod
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Re: E series RB upgrade

Post by Friedom »

I hear ya, but the site says very clearly that it's not a cleaning service, and that there should be no oil/gas/coolant lines on it. Almost like "send us a good carb if you want a great one back". I might be reading too much into it.

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Re: E series RB upgrade

Post by ohgood »

Friedom wrote:I hear ya, but the site says very clearly that it's not a cleaning service, and that there should be no oil/gas/coolant lines on it. Almost like "send us a good carb if you want a great one back". I might be reading too much into it.

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i have no experience with RB, other than he is one of the best, most knowledgable gurus out there, and he shares a LOT of it, even providing pictures of his divider plate work, on the internet.

i would imagine sending him a clapped out carb would be a bad idea, as it will cost more to have him diagnose each part, notify you, fix it, and THEN modify it, instead of just modifying a good condition carb.

the easiest way to ensure a GREAT carb would be, to ask him to modify a brand new one, and ship it to you.

i've seen the differences in wornout vs fresh carbs. i'm a buuuleeeever ;-)
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Re: E series RB upgrade

Post by Friedom »

Well here's a bright note. Took the bike out to do a 11 hr 4x trail. Lots of rocks, hill climbs, streams, etc. 1st serious ride with the DX. Power delivery was not exciting. I had to be really vigilant about stalling at low speeds. Figured just needed to get better at the clutch. Wasn't feeling confident, but making it work.
Then my buddy got his bike stuck in a stream, and when we got that squared away I came back to my bike laying on its side in the sand. Not a hint of starting to be had. Popped in a new plug, verified everything else in good order, and it started up. Happily. Then it ran really good!
Like scary good. Now I could blip across rocks again. Instead of needing the clutch to prevent stalling, I needed it to control wheely power delivery.
Yess. I love my bike now. Think I'll wait a bit on the air stryker. This bike is a handful again :)

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Re: E series RB upgrade

Post by Jaguar »

new carb, RB mod, whatever
2 strokes run differently with different weather, no matter what (except changing the jetting)
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Re: E series RB upgrade

Post by Friedom »

Jaguar wrote:new carb, RB mod, whatever
2 strokes run differently with different weather, no matter what (except changing the jetting)
Yes, but not as drastically different than I was experiencing. The new plug made a world of difference.

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Re: E series RB upgrade

Post by RockwoodKDX »

I had Ron do the head work on my 91 and also sent him the carb. Carb was worn out so bought a new one, not the Stryker. I have been extremely pleased with the improved performance. The front end lifts much easier and there is more power throughout. This truly woke the bike up. It is much more tunable as well. Small adjustments make noticeable changes to the bike. Additionally, I cut about two inches off the FMF muffler. This gave the bike a more distinct hit which I prefer. I can't say enough about Ron Black, very good service and quality work.

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