Heres some help for poor low end preformance

Discussion specific to the 1995 - 2006 KDX200 (H Series) and 1995 - 2005 KDX220R (A Series) models sold in the USA
bikeman2502001
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Re: Heres some help for poor low end preformance

Post by bikeman2502001 »

Here is a little better summery of the gas mileage difference I used to be able t ride 30 miles per tank Now I am able to ride 40 miles and have almost 2 quarts left Im pretty happy now thats acceptable and it runs awesome too boot
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MoonStomper
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Re: Source and part #?

Post by MoonStomper »

I noticed some wear on my slide when I recently installed a fresh kit. Mine runs pretty good, but always a little grumbly/less sharp off idle.
This sounds like worth a try... Where is the best place ya'll have found to source this slide? Part number?
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Let the good times ROLL!!!!!!!!!!!!!!!!
‘99 KDX 220 / '03 KDX 200 - @%@ '18 Trek Slash 8 @%@ ‘22 Rieju MR300 Racing

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bikeman2502001
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Re: Heres some help for poor low end preformance

Post by bikeman2502001 »

Sudco carburetor akways has all the carb parts you will ever need. I found mine on ebay there about 60 bucks. Please read the entire post here as the needle position is very different i have the sea level figured out for you should be good to 4000 feet or so the carburetor will be completely reprogramed
You will be grinning ear to ear. Smile
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Re: Heres some help for poor low end preformance

Post by MoonStomper »

QUESTIONS:
My H9 is still running the OEM pipe & OEM #5 slide (snorkle removed)...
Will this new #7 slide make the same improvements if still running the OEM pipe?
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Let the good times ROLL!!!!!!!!!!!!!!!!
‘99 KDX 220 / '03 KDX 200 - @%@ '18 Trek Slash 8 @%@ ‘22 Rieju MR300 Racing

BLACKSBURG, VIRGINIA USA
bikeman2502001
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Re: Heres some help for poor low end preformance

Post by bikeman2502001 »

Yes this cleans up all the jetting issues at the low end we all suffered from this in not just a high performance mod it will make any bike run alot better and now i can see it will pay for it self in gasoline savings a win win Any 2 stroke i ever buy that has a 5 in it will be changed before i even ride it i consider it a must have in my book.
To any one trying this at higher elevations remember if your bike bogs off idle in low end you need to raise the needle until it goes away the old ways of tuning doesnt apply anymore
bikeman2502001
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Re: Heres some help for poor low end preformance

Post by bikeman2502001 »

I have a cold weather update here now that some good air finally got to the south even i breath noticeably easier my bike went lean on me so bad it ran on in extended high rpm use and was bogging off idle. Even though my plug was picture perfect and my silencer was chalky coffey with cream i was very lean Not a big problem just needed to adjust a couple of things, remember if your bike is bogging off idle it is the pilot and needle position with the 7 slide. I am now at
45 pilot
Stock needle bottom 5th position
165 main
Air screw 1 turn out
Sea level 50 degrees
Also i believe it is a good idea to change the needle those of you with rb carbs could share your needle with us would be great i have purchased a Ktm needle for a 13 250 xcw for 10 dollars N8RJ as it uses a 36 mm carb abd a 7 slide as mine is after mod i havent installed it yet but it should give me even richer adjustments available when temps go down from here . I still believe now more than ever that this is the biggest mod to the rb carb not the divider as it has been an awesome mod much cleaner off of the bottom and noticeably better mileage at a total carb price of 160 good luck!
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Re: Heres some help for poor low end preformance

Post by KDXGarage »

CEK has been mentioned a lot over the years
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Re: Heres some help for poor low end preformance

Post by MoonStomper »

bikeman2502001 wrote: 10:57 pm Jan 01 2021 I have a cold weather update here now that some good air finally got to the south even i breath noticeably easier my bike went lean on me so bad it ran on in extended high rpm use and was bogging off idle. Even though my plug was picture perfect and my silencer was chalky coffey with cream i was very lean Not a big problem just needed to adjust a couple of things, remember if your bike is bogging off idle it is the pilot and needle position with the 7 slide. I am now at
45 pilot
Stock needle bottom 5th position
165 main
Air screw 1 turn out
Sea level 50 degrees
Also i believe it is a good idea to change the needle those of you with rb carbs could share your needle with us would be great i have purchased a Ktm needle for a 13 250 xcw for 10 dollars N8RJ as it uses a 36 mm carb abd a 7 slide as mine is after mod i havent installed it yet but it should give me even richer adjustments available when temps go down from here . I still believe now more than ever that this is the biggest mod to the rb carb not the divider as it has been an awesome mod much cleaner off of the bottom and noticeably better mileage at a total carb price of 160 good luck!
Bikeman...
You say "165" main and 45 pilot. That's richer than the 155 main for the #7 slide and less lean by one size on the pilot I saw recommended before (42 pilot/155 main/OEM needle). If you tried that (previously recommended) set up, what did you notice about it that caused you to change?

Regarding the needles. Do I understand correctly that the OEM needle has more abrupt transitions as the throttle increases where the CEK needle is leaner than OEM on the bottom with a more subtle change as throttle is added? Actually, after studying this chart... https://jetsrus.com/a_jets_by_carbureto ... 27-48.html
I realize that I need to find out what the OEM needle actually is (where I'm starting from) and where it falls on the chart - or rough equivalent - in order to know which direction I'm going. Does anyone know the code for the OEM needle (H9 model)? Is it the 1173, which is like a CEP?

KDXGarage...
Where do you purchase your needles, JetsRUs?
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Let the good times ROLL!!!!!!!!!!!!!!!!
‘99 KDX 220 / '03 KDX 200 - @%@ '18 Trek Slash 8 @%@ ‘22 Rieju MR300 Racing

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Re: Heres some help for poor low end preformance

Post by KDXGarage »

I haven't purchased in a long time, but sudco or jetsrus are the two places that many have had success with.
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Re: Heres some help for poor low end preformance

Post by kdxdazz »

1173 is a beq equivalent
1999 KDX220SR (KDX220-B5)
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Re: Heres some help for poor low end preformance

Post by kdxdazz »

Sorry I meant the 1174 is beq equivalent
1999 KDX220SR (KDX220-B5)
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Re: Heres some help for poor low end preformance

Post by bikeman2502001 »

Im sorry for the late response ive been busy lately the reason for this change is actually 2 reasons the first is cool weather made it here finally holding alot more oxygen for us its usually hot 100 degrees and very humid causing us to have to lean out our jetting pretty much the difference is pretty drastic second i changed fuel companies from shell to other suppliers and the performance difference is very noticeable i even got a tank of completely bad gas from shell i took out good gas and put bad in lol. Ive never had a bike run so crazy in my life i had virtually every symptom in the book all at one time i just went back home changed to another brand and its been running better ever since. I informed the manager and of course i got the standard corporate america answer Thats impossible we never have these kind of troubles but ive worked in dealer ships for 30 years i know better i just told her to pay the repair bills and walked out not my problem at that point. Remember old needle settings will not be anywhere close with the 7 slide it will bog bad in the 1st 2nd and 3rd positions with the stock needle Im an absolute believer in this mod and it does give me a good 10 miles more per tank paying for it self in the long run carburetes much better down low making the mid and top so much cleaner as its not to fat down low causing a sluggish mid to top try it you’ll like it
bikeman2502001
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Re: Heres some help for poor low end preformance

Post by bikeman2502001 »

How i noticed i needed to make a change was after a straight away my bike would run on or scream when i closed the throttle and the kill switch would not stop the engine if that would happen in the woods i would hope the recalculate route button was working properly lol My plug and silencer was as picture perfect as anyone could ever wish for thats why i warn people about plug chopping on the street that does not load the motor at all like sand does it is better to have the plug a little dark on high performance 2 strokes or they can run on you when high engine speeds and load comes in to play we have all the sand you could ever ask for here
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Re: Heres some help for poor low end preformance

Post by MoonStomper »

Haven't done this mod yet - just too much else happening and we're doing the Sumter Enduro in a couple weeks.

QUESTION: I'm at 2k' ELE here in Blacksburg, VA, and the bike is running great right now in our late January 40-50 degree temps. Dropping down south to Sumer, SC for the enduro next weekend would any of you suggest any pre-emptive jetting adjustments or just wait and see what she feels like morning of? Not too familiar with what to expect - they are under 200' ELE. and averaging mid-fifties temps.

I appreciate any thoughts!
~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~^~
Let the good times ROLL!!!!!!!!!!!!!!!!
‘99 KDX 220 / '03 KDX 200 - @%@ '18 Trek Slash 8 @%@ ‘22 Rieju MR300 Racing

BLACKSBURG, VIRGINIA USA
bikeman2502001
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Re: Heres some help for poor low end preformance

Post by bikeman2502001 »

Actually you shouldnt have alot of trouble from a 1500 feet elevation difference and not too extreme temperature difference people usually change at 4000 feet and so on. I rode my yz 250 with sea level jetting all the way to 13000 feet with only normal high altitude loss no fouling and met many at the top doing the same not saying that was optimal by any means but not as bad as you would think either
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Re: Heres some help for poor low end preformance

Post by MoonStomper »

That's what I was guessing - thanks for the confirmation!!!
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Let the good times ROLL!!!!!!!!!!!!!!!!
‘99 KDX 220 / '03 KDX 200 - @%@ '18 Trek Slash 8 @%@ ‘22 Rieju MR300 Racing

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Re: Heres some help for poor low end preformance

Post by KDXGarage »

take a few plugs and don't forget to tune that air screw!
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Re: Heres some help for poor low end preformance

Post by Guinness Dave »

I just ordered a #7 slide for my pwk35 quad striker. $75 from jets-r-us. Note: the Sudco catalog lists different #7 slide part numbers for the different PWK35 carbs. I assume they are the same actual part, but, cannot confirm. Will update when it arrives. I've got a '96 stock 200.
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Re: Heres some help for poor low end preformance

Post by Guinness Dave »

Are you still happy with the latest settings Bikeman? I just gotta #7 slide and a CEK needle and excited to try and install and tune it.
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Re: Heres some help for poor low end preformance

Post by Bauer9168 »

Any updates? Anyone know how to decode/tell if you have a 33 or 35? My 220 has some visible machining marks at the bore, but I don’t have a good way to measure. I don’t have any significant issues with the bike, but it smokes a little more than I’d expect I have a fair amount of drool from the silencer.

I’m at sea level, Rev pipe, snorkel removed. I’m running 40:1, so it’s a bit more fuel than factory, but I’m down to a 35 pilot at this point, about 1.5 turns out on the air screw. My main is a 140, and the top end falls off more than I’d guess is normal. Im hoping this slide might help, just looking for more input. As is- it is super smooth down low, and I’d say I lug the **** out of it, I’m just hoping to get rid of the goo/smoke a little less.
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