2001 CR250 carb sucks

[YZhallsme]

Dogger thanks for the link. Heres one you might find usefull, a memeber from another site had both the S66 and the 00' carb and notes some differences, and jetting info. Sorry I looked for this earlier but couldn't find it. [Only registered and activated users can see links. ]

[dogger315]

Thanks, good info and an excellent baseline to start from for jetting.

dogger

[bundyho1]

Originally Posted by YZhallsme

Dogger your welcome. Now I'm hoping you can educate me. I've seen you post the carb ID #'s a few times. I was wondering if there is a place I can go (other than the manual) to find these identification #'s? For those that may be interested the identification # stamped in the 00' CR 250 carb is PWK00B. I'm wondering if the 99' CR 250 carb ID # is PWK00A??

---------- Post added at 08:23 PM ---------- Previous post was at 06:53 PM ----------


Could you clarify which parts you ended up with? V-force III or V-force Delta II, and wether or not you had to cut the insulator (stuffers) off? Also if you get a chance can you measure the overall length (inlet to outlet) of your stock Mikuni TMX?



Sorry but I haven't made the switch from the TMX to PWK so I have no clue. It might be best to use the info. from those that have. One thing you might want to make note of and/or post, is your throttle valve (slide) number. Keihin makes them with several different cutaways. [Only registered and activated users can see links. ]
The cutaway will have an effect early in the throttle range. See the graph and #7 [Only registered and activated users can see links. ]

Over the last two years I've read many many threads about this. I can't recall anyone (zero, zippo, nada) ever going back to the Mikuni!

Sorry i missed this q. but i have the v-force3 reeds and i did have to cut the stuffers off of the new boot(that really sucks doing this to a new piece) but i did it and will try and get some mesurements today if it doesnt rain here when i get off of work at 4pm also what the eastest way to put tis new carb in?I have heard some people remove the sub frame to get it in...

[dogger315]

Before you mount the intake, could you take a picture of the modified
side for avi-b so he can see what it's supposed to look like. I would
do it but I already mounted mine and would have to replace the gaskets
if I took it apart again.

what the eastest way to put tis new carb in?

Personally, I always remove the subframe when messing with the carb.
I don't have the patience to wrestle with the carb boot in such tight
conditions. I mount the carb, install the throttle cable, route all the
vents, spray some silicon lube on the intake bell and rubber boot to
help ease the install when reattaching the subframe.

dogger

[bundyho1]

Sorry man,i have already installed it .Well i had to take the subframe off to get the carb in.It was a pain in the A.But it was well worth it .Man this thing flat rips now.Would i do it over again ,In a heart beat.Its a little lean on the pilot.42 in it now but the air screw does respond when screwing it in to about under 1 turn.Im at about 900ft above sea level.80temp.So i think right now i will end up at 45 pilot a 1370DKA needle on the 2nd clip with a 178 main.The main might still be a little fat but its ok.Feel like the (cr85 has no lowend ) now with no hesitation through the whole throttle range. That needle is from the 99 250.

Here is a link to cutting the stuffers from the boot

V Force Delta 2 Reed Valve Install

[dogger315]

Man this thing flat rips now

Good news. That's the way it should be.
Fine tuning the jetting should be a piece of
cake now.

dogger

[YZhallsme]

Originally Posted by bundyho1

Well i had to take the subframe off to get the carb in.It was a pain in the A.But it was well worth it.

Ha Ha, I remember the first time I yanked the subframe and shock to pull the carb, I thought it was a PITA too. I've done it so many times now, it's simple. Sounds like your another in a long list of satisfied PWK users. As said before it always turns out this way in the threads I've read. Don't know why I continue to mess with the TMX?
As for the measurement, I found what I was looking for. Overall inlet to outlet.
01'-03' CR 250 TMX = 86mm
04'-07' CR 250 TMX = 75mm

One thing to keep in mind when trying to make a different carb fit in the existing space is the use of reed spacers or maybe even the V-force. I noticed in doggers final installment of the CR motor build he starts with the stock reed cage but ends with a V-force. It looks to be quite a bit thicker than the stock cage in the picture.

Dogger can you measure the difference?

[dogger315]

he starts with the stock reed cage but ends with a V-force.

You noticed. I thought it would be helpful to more people to detail a stock
reed cage install rather than the VForce.

can you measure the difference?

The stock cage and intake flange is 9mm. The VForce, modified intake
flange and extra gasket total 12mm.

dogger

[bundyho1]

one thing i noticed even with the new 2000 carb insulator the card doesnt completely fit in the air box boot all the way.(cr250-2001)i also have vforce3 reeds
also i found this link
[Only registered and activated users can see links. ]
OK here is my settings
45 pilot a 1370DKA needle on the 2nd clip with a 178 main.running really good at 80temp with 50% humidity .900feet abouve sea level

[Faded]

Originally Posted by bundyho1

one thing i noticed even with the new 2000 carb insulator the card doesnt completely fit in the air box boot all the way.(cr250-2001)i also have vforce3 reeds
also i found this link
[Only registered and activated users can see links. ]
OK here is my settings
45 pilot a 1370DKA needle on the 2nd clip with a 178 main.running really good at 80temp with 50% humidity .900feet abouve sea level

That's a good thread and this one has been great as well. You problably still have room to safely lean out your pilot (1 step) and your main (1-2 steps) from where you're at right now.

[bundyho1]

Well i tried the 42 pilot first an it was on the lean side ,high idle so i tried the 45 and now she purrs like a kitten yea i think i could go a 1 more down on the main but im going to wait until it gets colder and see how it does

[1promodfan]

O.K. I've been reading this thread and I still haven't found the answer. Did the 2000 CR250 come with the Keihin 38mm airstryker??

[dogger315]

Did the 2000 CR250 come with the Keihin 38mm airstryker??

Yes. The 1999 and 2000 were both equipped with that carburetor.

dogger

[bundyho1]

Another + to this has been the gas mileage it doesnt burn half as much gas as it used to.I have noticed that it loads up really fast when you putt around even after the carb swap but it is alot better.

[bundyho1]

here are some pics
[Only registered and activated users can see links. ]

[motoxr99]

ok, i have been reding this thread. i have a 98 yz250 that has the pwm carb, i dont care for it. i want to mount a pwk. back earlier in the thread, there was a part# one of you guys supplied and pic of a new carb in a bag. i need the shorter more compact bodied carb. the 75mm version. is that honda part# what i am after? i would buy one of the tomorrow if i knew it was the carb i am looking for. i need the 75mm body and a 38mm carb. hoping finding this new board will help me get that PWM carb outta my life!

[dogger315]

there was a part# one of you guys supplied and pic of a new carb in a bag...is that honda part# what i am after?

No. The Honda carburetor is over 90mm front to back. I don't know which
PWK has the shortened body. You might try PMing YZhallsme and asking,
he was the one that had that info.

dogger

[motoxr99]

had to leave him a visitor message as i dont think i have the post yet to pm someone. hope to hear from him soon as i cant wait to ditch this pkm carb

[YZhallsme]

Originally Posted by motoxr99

ok, i have been reding this thread. i have a 98 yz250 that has the pwm carb, i dont care for it. i want to mount a pwk. back earlier in the thread, there was a part# one of you guys supplied and pic of a new carb in a bag. i need the shorter more compact bodied carb. the 75mm version. is that honda part# what i am after? i would buy one of the tomorrow if i knew it was the carb i am looking for. i need the 75mm body and a 38mm carb. hoping finding this new board will help me get that PWM carb outta my life!

I don't know this for sure but think that the PWK's with the rectangular top retained by screws, are the shorter 75mm PWK's and that those with the round twist on top have the longer 91mm body. Whats wrong with the PWM?

[motoxr99]

just doesnt carb well at low speed from what i have exp so far. plus i hare scramble and enduro and the pwk gets better fuel mileage.