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mixxer

Keihin PD Super Pumper Carb/ TURBO

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Pump shot capacity and duration can be a real pain to get right.  If the nozzle is too fine/small you get a great shot with small position changes but not enough total volume at WOT from small opening.  If the nozzle is too large you get a great full-capacity volume shot at WOT from small openings BUT you get dribble with small position changes.  Dribble drops out and can be worse than no shot at all.

I can only imagine this gets even ore difficult to tune with tiny carbs and engines.  This is one of the reasons I am a huge fan of Honda's early RFVC dual-carb setups and Yamaha's YDIS setups.  You get good response at just about every throttle position.  The dual-carb XR250s and XL600 we had were pretty amazing as far as best of both worlds.  Great low-mid and great WOT.

The two carbs on my SRX600 single are on the small side (2x27) but the result is brutal instant throttle response at all engine speeds.  Since the thing never sees more than ~7,000 RPM the carbs are sized close enough for the sort of riding I do.

IMG_1725.JPG

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Live action photo of the pump shot aiming where I am more than happy...

You can maybe see the nozzle has been "stressed into final shape" 

This fine adjustment was made possible by Channel Lock Corp.. lol

IMG_20170807_152727.jpg

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4 minutes ago, mixxer said:

Live action photo of the pump shot aiming where I am more than happy...

You can maybe see the nozzle has been "stressed into final shape" 

This fine adjustment was made possible by Channel Lock Corp.. lol

IMG_20170807_152727.jpg

For heavens sake put that thing on! Lets hear about how it runs..................... :) 

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Attention to detail at this degree could be considered a little OCD. Secondly I must say you have done wonders with your Chinese knockoff of a Taiwanese knockoff of a Japanese carburetor. Can't wait for the ride report.

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1 hour ago, Confederate said:

Attention to detail at this degree could be considered a little OCD. Secondly I must say you have done wonders with your Chinese knockoff of a Taiwanese knockoff of a Japanese carburetor. Can't wait for the ride report.

Lol!!

Well said on the knock off chain!!

With people saying that the OKO pwk knock offs were fairly decent... I was hoping that would be the case with this carb...

So far all the crap wrong with it has been remedied... Stuff like stripped screw heads and the slide screws not being tightened would be an inconvenience..

The throttle cam not being clocked correctly would have had about 3mm of venturi still blocked @WOT... So not something that would make it not run, but for sure be down on potential power...  

I was able to cut the stop tab down on the throttle cam enough to allow me to get 2~3 mm additional throttle opening out by cutting the venturi roof higher... But that was with cutting the the throttle stop tab as far as I could... Had it been clocked correctly perhaps I could have raised the venturi roof even higher...

But in any event, anyone not cutting the throttle stop ,simply would not have had full venturi opening available... Not good...

Then we have the pump shot nozzle shooting the pump shot on the floor of the carb, before the back of the slide... Basically rendering the whole purpose of this carb... The accelerator pump... Entirely ineffective ...fixed now... but Junk without intervention...

I had also decided to nix the whole choke plate and axle obstruction... Shooting for max performance potential ... And knowing I can twist the throttle and throw a couple pump shots in, to help with cold start, makes me want to gamble on no choke being ok...

I should be able to have time to install and test the carb, maybe tomorrow.... This weekend at the latest...

 

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mixxer,

Which carburetor are you referring to, as I had considered one for the XR200R, although we are down on cc's, we have a slight stock compression advantage ?

The one I was considering was the following on Ebay wi the dual pull cable. http://www.ebay.com/itm/Keihin-PZ30-Accelerate-Pump-Carburetor-Repair-Throttle-Cable-200cc-250cc-Dirt-/322432467633?hash=item4b127902b1:g:VXsAAOSw3v5YrqyW&vxp=mtr

I had the Mikuni TM33 pumper carb on my old KLX331 and loved that thing, so was looking for something similar for the XR200R. 

Thanks for taking the time to share this thread.

Michael 

 

 

 

 

 

 

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8 minutes ago, KTM520EXC said:

mixxer,

Which carburetor are you referring to, as I had considered one for the XR200R, although we are down on cc's, we have a slight stock compression advantage ?

The one I was considering was the following on Ebay wi the dual pull cable. http://www.ebay.com/itm/Keihin-PZ30-Accelerate-Pump-Carburetor-Repair-Throttle-Cable-200cc-250cc-Dirt-/322432467633?hash=item4b127902b1:g:VXsAAOSw3v5YrqyW&vxp=mtr

I had the Mikuni TM33 pumper carb on my old KLX331 and loved that thing, so was looking for something similar for the XR200R. 

Thanks for taking the time to share this thread.

Michael 

 

 

 

 

 

 

Nope, that link goes to a different style carb.... I had a modded xr212 setup I loved years ago, but I don't remember how the carb mounted to the manifold... The 230 setup has a spigot that fits inside the rubber manifold and is held tight with a clamp... Plus that carb looks to use a single throttle cable...

If you do a search for xl250 carb, it will pull up hundreds of the carb I'm working with... Dual throttle cable..

Edited by mixxer

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mixxer,

Nope that's dual throttle cable, it is not like the push pull type that come on the FCR's, but is split ~ 1/2 way down, 1 operates

the throttle slide, the other operates the accelerator pump, so you can adjust the accelator pump at the carb, which you could not

do on the old TM33's. 

 

The XR200R's carburetors are your typical old school mounting of 2 nuts onto the manifold after you slide the carburetor body over

2 bolts that are recessed into the rubber manifold. The rubber manifold itself is ~ 2" long, which is not straight, but off to a slight 

angle, but you can certainly get a straight shot in through the intake manifold into the cylinder head w/o obstruction. 

 

Again, just asking for the Ebay link what you are working on, as I understood the thread it was based on the PD97, which is on

all 86-02 XR200R's, save for a couple of slight exceptions, i.e. the California carburetors come slightly leaner.

 

Thanks !!! Michael 

 

 

 

 

 

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This is the Chinesium copy that mixxer is modifying in this post

http://www.ebay.com/itm/253007290272?rmvSB=true

This has identical throttle cable configuration of the 230f stock carb, and same carb body. This carb is a copy of a carb from a late 70's (78?) XL250s. not like the PD97 link you provided.  See this thread for the origination of the find, 

 

Edited by NEODS
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 Sorry I didn't get back in time..

NEODS nailed it with his link.. that's the carb...

Interesting about the separate throttle cable for slide and accel pump... Have not dealt with one of those

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2 hours ago, KTM520EXC said:

mixxer,

Nope that's dual throttle cable, it is not like the push pull type that come on the FCR's, but is split ~ 1/2 way down, 1 operates

the throttle slide, the other operates the accelerator pump, so you can adjust the accelator pump at the carb, which you could not

do on the old TM33's. 

 

The XR200R's carburetors are your typical old school mounting of 2 nuts onto the manifold after you slide the carburetor body over

2 bolts that are recessed into the rubber manifold. The rubber manifold itself is ~ 2" long, which is not straight, but off to a slight 

angle, but you can certainly get a straight shot in through the intake manifold into the cylinder head w/o obstruction. 

 

Again, just asking for the Ebay link what you are working on, as I understood the thread it was based on the PD97, which is on

all 86-02 XR200R's, save for a couple of slight exceptions, i.e. the California carburetors come slightly leaner.

 

Thanks !!! Michael 

 

 

 

 

 

Well now you've jolly well done it, Michael!!

That carb is a cleaner/ simpler design ...

30mm out of the box... With accelerator pump....

 

An xr200 manifold maybe would adapt it, but if not , an adaptor would be simple to fabricate...

Where were you a couple weeks ago when all this started?? Lol

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2 hours ago, mixxer said:

 Sorry I didn't get back in time..

NEODS nailed it with his link.. that's the carb...

Interesting about the separate throttle cable for slide and accel pump... Have not dealt with one of those

I looked at those but did not find any throttle cables for them. Would like to see someone try one out!

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2 hours ago, ricky racer said:

I looked at those but did not find any throttle cables for them. Would like to see someone try one out!

I checked a bit on eBay and some of these carbs are in the $30 range for carb and cable included...

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Chinese stuff are so doubtful in terms of quality that when they try to copy a xl's carburetor, the final product is a (BR model) xr200 carburetor copy 😅

That is the original xl carburetor, the venturi and the "throat" are huge in comparison to the xr200 ☻😍 haha 

20170809_190130.png

20170809_190051.png

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20 minutes ago, mixxer said:

I checked a bit on eBay and some of these carbs are in the $30 range for carb and cable included...

That's cool. I didn't see any with a cable about a year ago when I was first trying to figure out a pumper carb for mine. Hope you get to try yours out soon. I want to see if it runs good out of the box. Not that I need one now lol

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1 minute ago, RND.23 said:

Chinese stuff are so doubtful in terms of quality that when they try to copy a xl's carburetor, the final product is a (BR model) xr200 carburetor copy 😅

That is the original xl carburetor, the venturi and the "throat" are huge in comparison to the xr200 ☻😍 haha 

20170809_190130.png

20170809_190051.png

This is what I have and love it!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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This is what I have and love it!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!



Size matters....
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3 hours ago, RND.23 said:

Chinese stuff are so doubtful in terms of quality that when they try to copy a xl's carburetor, the final product is a (BR model) xr200 carburetor copy 😅

That is the original xl carburetor, the venturi and the "throat" are huge in comparison to the xr200 ☻😍 haha 

20170809_190130.png

20170809_190051.png

Thanks for the pics...good add...

I have zero doubt about the questionable quality of 3rd world manufacturing!!

If I find a good deal on one of these, I will probably snag it

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