Standard KDX 200 or 220 carb as a replacement for a 220 SR?

A reference for the PWK carbs...
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crs
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Standard KDX 200 or 220 carb as a replacement for a 220 SR?

Post by crs »

I replied to a thread on jetting but realised it is in the General section and should really be in over here... My reply's below - the rest of the thread is: http://www.kdxrider.net/forums/viewtopi ... 77&t=13583
So I've got a 220 SR and am looking to find either a 33 or 35 used carb to put on it...

Reading this it seems like the standard 220 carb is too rich as it comes so the cheapest upgrade is a standard 200 carb as then no messing changing needles and expensive slides - just jets and maybe clip position.

I ride steep, slower single track stuff a lot at around 1000m - and it gets v. hot and humid (N. Thailand). I really don't care about a flying top end or want a snappy powerband as can hardly use it round here - a good low / mid spread is most important.

Thoughts? Is the standard 200 or 220 carb the way to go for what I need? (People always have to lean out carbs a fair way for riding round here as some altitude, hight temps and v. humid for part of the year.)

Also, I might try to mod the standard inlet to fit the SR autolube in - anyone done this?

Cheers.

(Yes, I know about RB but that's a lot more $ and it's a PITA for me to even buy from the man - maybe a mod for next rainy season.)
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Re: Standard KDX 200 or 220 carb as a replacement for a 220

Post by Jaguar »

you are talking about riding speeds at which you aren't full throttle so I don't know why you think a bigger carb will help.
Bigger only helps at top RPM.
Correctly jet what you have.
Make sure you have good engine compression.
Put in an Iridium plug.
Make sure your silencer isn't restricting flow because if it is that creates pipe backpressure which negates the pipes return vacuum wave which is essential for low RPM power.
Try a smaller countershaft sprocket.
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Re: Standard KDX 200 or 220 carb as a replacement for a 220

Post by crs »

Why a bigger carb? From people's opinions and reviews I've read here and elsewhere, many say putting the 200 carb on the 220 is good - and that you only lose a little bottom end over the 33 carb - the guy in the thread I linked to says he uses it for slower riding. (And made it sound easier to get the standard 35 carb running right as is, compared to the 33 as the 33 slide is too rich - this is what I was trying to clarify.)

Note, I have an SR model - it came with only a 28mm PE carb - with narrower pipes either side. A 30mm Keihin copy has been put on but I still think at least a 33 is worth a try - see if it'll open up power delivery across the range better. I think it's too restricted as is - and I'm not bothered about top end but would like more mid.

I'm probably going to go for the 33 - just hope that the standard slide and needle will work OK where I am.

Thanks for your suggestions - I'll get an iridium plug - didn't think about that..

Cheers.
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Re: Standard KDX 200 or 220 carb as a replacement for a 220

Post by Bitteeinit »

Interesting. I also have an SR but I'm not sure what carb I have on it. It's definitely not stock, probably from a 220 or a 250 (I have a 200). Is there an easy way to ID a carb? Sorry for the thread highjack.
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Re: Standard KDX 200 or 220 carb as a replacement for a 220

Post by crs »

There should be markings on it for 'Keihin', 'PWK', 'PE', etc. If it doesn't have Keihin on it then it's maybe a copy. You can measure to see what size it is.
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Re: Standard KDX 200 or 220 carb as a replacement for a 220

Post by Bitteeinit »

It's a keihin, I remember that much. Where exactly do I measure to know the size? Pardon my...ahem...ignorance....
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Re: Standard KDX 200 or 220 carb as a replacement for a 220

Post by crs »

Measure inside the engine side, I think.
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Re: Standard KDX 200 or 220 carb as a replacement for a 220

Post by Postigo »

Hi, if your bike is a 220 I recommend the 33mm pwk with the scarry fast attachment. Your bike will run better since the 35mm will only help your bike at top speed at the expense of bottom end and mid range.
I have both carbs and for my KDX 220 American version the 33mm pwk is the one I prefer, crisper response and better mid range. As a side note I'm assuming that the 220 American version and the 220 SR have the same porting characteristics.
At this photos you can see the difference between the two carbs. The one without the slide is the 33mm and the other one is a 35mm pwk.
ImageImage
First make sure what carb size you have on the SR by measuring the inside of the intake area diameter (the area connected to the reed cage) with a Bernier caliper. Hope this helps.


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Re: Standard KDX 200 or 220 carb as a replacement for a 220

Post by crs »

Is that the PowerNow or the PowerNow Plus or both you're using? Big difference?

I would think that the porting is the same between the standard 220 and 220 SR.

Mine's already had the head skimmed down to the 200s spec, apparently.
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Re: Standard KDX 200 or 220 carb as a replacement for a 220

Post by Postigo »

That's the scarry fast power now and it works really well in my bike, more crisper and a smooth transition from bottom to top end. My jetting is 38/138 at sea level with hight humidity and temps between 80 and 95 deg. She is a torque monster with stock gearing 13/47 and my top speed is 72mph I can't ask for more. :supz:
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Standard KDX 200 or 220 carb as a replacement for a 220 SR?

Post by cornishwrecker220 »

You can`t just swop carbs on the SR...you will need to replace the carb boot & possibly reed block assembly ...also the air box boot will be need to changed too to allow for the larger 33 or 35 mm carb, possibly the whole air box from the 220 ( as the SR version is smaller where it mounts to the carb )....with regards to the 35mm carb on the 220, I run one & its great...you don't even notice any bottom end loss...its all in the mid range that this bike will benefit from having the larger carb.
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Standard KDX 200 or 220 carb as a replacement for a 220 SR?

Post by crs »

cornishwrecker220 wrote:You can`t just swop carbs on the SR...you will need to replace the carb boot & possibly reed block assembly ...also the air box boot will be need to changed too to allow for the larger 33 or 35 mm carb, possibly the whole air box from the 220 ( as the SR version is smaller where it mounts to the carb )....with regards to the 35mm carb on the 220, I run one & its great...you don't even notice any bottom end loss...its all in the mid range that this bike will benefit from having the larger carb.
Yep, need to change the inlet boot and boot to air box. Reed block same.

Yes, it was you're comments in the other thread that made me think about just going straight to a 200 carb. Are you using the standard 200 carb needle and slide when it's on your 220? Your sea-level in UK, iirc - I'm far hotter, more humid and bit higher up in N. Thailand so will have to set the carb up leaner.
Last edited by crs on 06:11 am Oct 05 2014, edited 1 time in total.
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Re: Standard KDX 200 or 220 carb as a replacement for a 220

Post by crs »

Postigo wrote:That's the scarry fast power now and it works really well in my bike, more crisper and a smooth transition from bottom to top end. My jetting is 38/138 at sea level with hight humidity and temps between 80 and 95 deg. She is a torque monster with stock gearing 13/47 and my top speed is 72mph I can't ask for more. :supz:
Are you using the standard needle? What clip positions? Sounds like I've got similar conditions to you - just I'm riding hills around 1000m.

Cheers.
Last edited by crs on 08:13 am Oct 05 2014, edited 2 times in total.
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Standard KDX 200 or 220 carb as a replacement for a 220 SR?

Post by cornishwrecker220 »

I run the 35mm carb, with the 220 needle in the mid position ...slides are the same on the 97-05 200/220...but not the early 200 slide as they have a richer cut away I think ( 6 or 5 ? ) ..I`m at sea level & use a 38 pilot & 152 main...I have also run the carb off a 1990/1991 kx 125 ( pkw 36mm )....you do notice a very slight drop in torque down low, but a much stronger pull from the mid range up.

You can convert a SR 220 with a little time & money...but to be honest its probably not worth all the aggro ....just run it as it is or sell up & by the full endure spec 220..
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Standard KDX 200 or 220 carb as a replacement for a 220 SR?

Post by crs »

cornishwrecker220 wrote:IYou can convert a SR 220 with a little time & money...but to be honest its probably not worth all the aggro ....just run it as it is or sell up & by the full endure spec 220..
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