Attn: 2002/2003 CR250 Keihin PWK Converts

Dragmeistr

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Oct 14, 2002
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Its been awhile since I have messed with it, but I will dig into it for you soon and get back with you. The needle I am running is a CPW needle so it is of the 3 letter type. I am pretty positive that I have a 175 main in it now, pretty positive that its a #7 slide, but I will get the rest for ya.
 

Farmer John

T.C.F.<br>(tire changin' fool)
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Mar 8, 2000
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I have been staying out of this thread because I just got my 03 last Friday (10/17) & wanted to try some stuff before chiming in. Please keep in mind, this bike is stock with a FMF turbine core S/A & steel clutch plates, and I run it on 92 pump swill w/ HP2 @ 40:1.

I tried approx 12 different set ups with the Mikuni & was not ever able to eliminate the weak/lean bottom feeling without screwing up the transfer to mid/top end.

On Tuesday I put on a 38mm PWKa/s I tried a few set ups & ended up with:
Slide - 7
Needle - A715/289R/A327/A487
Clip - middle groove
Pilot - 45
Main - 172
A/S - 1-3/4 out

with this set up it has good smooth response, but does get little black speckles on the fender. I'm thinking lowering the needle 1 clip will clear that up

I just got done installing a V-Force reed cage & will start messing with that in the morning.

All in all I really like the bike. I am waiting for UPS to deliver my GPR stabilizer & Moose tall seat.
The only other mods I have done are Tag CR double high oversized bars, hand guards, Clarke tank, Devol skid plate, a read master cylinder cooling extension thing, o-ring chain, & put my enduro computers & sensor on.

oh yeah....I pitched that p.o.s. front Dunlop.... that thing was just plain evil.
 

Eiswald

Member
Aug 13, 2002
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Mr Farmer John where did you get your carb from and was it anywhere close to being jetted? I too have an 03 CR 250 and have tryed alot of thing from slides, nozzles, needle to jets. I got it to run great but it pings in low-mid and finally cracked a small piece of the top of the piston on the exaust side. The funny thing is it does not seem to be lean. I even richened up the pilot and needle but no better, Just ran crappy! If I could bolt on a carb that fixed this I would be elated. Thanks
 

Faded

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Jan 7, 2003
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Originally posted by Farmer John
I tried approx 12 different set ups with the Mikuni

That's it? :confused:

Farmer John, thanks for the info, I appreciate it. It sure didn't take you long to make the switch to the PWK. BTW, what altitude are you at? If I could get mine smooth I wouldn't mind the little black specs on the rear fender.
 

James

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Dec 26, 2001
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I usually have some black specs on the fender (on all of my CRs). If it runs right, I don't care if it gets oily or dirty.
 

Faded

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Jan 7, 2003
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Originally posted by Farmer John
oh yeah....I pitched that p.o.s. front Dunlop.... that thing was just plain evil.

Wise decision on the front tire...make I make a suggestion for the rear?
1066931477_02CRburnout_1.jpg

:)
 

Farmer John

T.C.F.<br>(tire changin' fool)
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Mar 8, 2000
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Originally posted by Faded
Farmer John, thanks for the info, I appreciate it. It sure didn't take you long to make the switch to the PWK. BTW, what altitude are you at? If I could get mine smooth I wouldn't mind the little black specs on the rear fender.

I am at 750ft elevation, & most of my riding is below 6000ft.
I don't really care about the specks, but they are a kind of confirmation that I'm not quite there, yet. The bike is smooth, but I now feel it is a touch rich every where, but not plug fouling bad.
 

Dragmeistr

Sponsoring Member
Oct 14, 2002
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OK, checked my jetting this weekend:
#7 slide
DGK needle 3rd clip
45 pilot
1 3/4 AS

Im in Phoenix which is what? about 800 ft elevation and has been over 95 degrees until this last weekend. This is on C-12 fuel at 32:1 with Honda HP2. Mods include, V-force (high tension setting), SST pipe & silencer, Boyeson flange, Power Now insert. No spooge, just some specs on my white rear fender from time to time.
 

Faded

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Jan 7, 2003
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Dragmeistr,

Thanks for the specs. If I'm lucky I'll be getting a PWK around Christmas so next year will be yet another learning experience. :silly:
 

scroskrey

Member
Jul 5, 2003
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Sorry about the late entry to this discussion. I have been following this and many other threads elswhere trying to get a handle this subject. I have a 2001 CR250 with SST pipe, Power core II silencer, Boyesen RAD valve, Boyesen power valve cover and now Eric's Mo power everywhere porting. Problem is I haven't found more power anywhere. Prior to the porting I was running a 25 pilot, -76 needle in 2nd groove, stocke slide with 2 mm shaved from cut-away, stock needle jet and a 380 main. I have been chasing the jetting for several months now. I cannot find any pilot from a 12 to a 37.5 that will allow the engine to idle. I have NO off idle response. Only "baawwgg". I have finally acheived throttle response from 1/2 throttle and higher but I feel it still falls short of its potential. I have every pilot from 12 to 37.5, S-4, S-7, S-8, S-9 needle jets, stock and several shaved slides, -72 thru -76 needles and mains from 300 to 450. Somewhere in that mess should be a combo that works!?! I'm at 2000 ft with temps from 100 to 110 summer, down to 50 in the winter. Sorry about the long winded post but there seems to be many knowlegable and experienced people here. I appreciate any help you guys may have to offer.
 

marcusgunby

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Jan 9, 2000
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Sounds like you are now too lean on the slide- maybe the porting doesnt like the leaner slide and so your problems come from there.
 

Faded

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Jan 7, 2003
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Originally posted by scroskrey
Prior to the porting I was running a 25 pilot, -76 needle in 2nd groove, stocke slide with 2 mm shaved from cut-away, stock needle jet and a 380 main....

What jetting are you running now? I'm with Marcus, with the modded slide, lean needle and small pilot I would say you're lean.
 

bclapham

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Nov 5, 2001
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i rode a 2003 cr250 on sat- v-force and pc pipe no porting, it felt small for me but was setup for a smaller rider- i was real impressed, it feels like a 125 (light and turns real well) but with a ton of nice power- didnt notice a lack of bottom either but i didnt ride it hard- we were trying to chase down noise from the chain, when i rode it though, i thought it was detoing somewhere from 0 to 1/2 throttle, but we have to put more time to figure it out.
 

James

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Dec 26, 2001
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The more seat time I spend on the CRs, the more I notice the "bottom end" or lack thereof on the 02 as compared to the 00. It is so far on the bottom though that I only notice it when really lugging through turns. It is a bit harder to ride the 02 "slow", and when it comes on it is hard to keep the front wheel down. The 2000 has made an excellent woods bike thus far....I don't expect to make the same transformation as successfully with the 02. I guess that's ok, won't hurt to have a dedicated MXer.

I think I am going to check and see how well the 00/01 motor fits in the 02 frame during my post ACL off time....has anybody heard of this being done??
 

parkerCR

Member
Nov 8, 2001
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Faded,

I was having all the usual problems with jetting my 01 CR250. Different nozzles blah, blah, blah. I got the keihin from CPW and they jetted it for my mods. I have mo betta from Eric and it seems to run a lot cleaner. I think that the main jet will most likely be the one that will need adjusting which is easy. It fits pretty well except the front is snug on the boot and the rear is loose but the screws can be adjusted to make it fit fine. Although I haven't had a tremendous amount of experience with the new carb yet it seems to run cleaner and anything to avoid ripping into the carb every hour during a ride is greaty by me. I would order it from Service Honda and save yourself
60.00. Good luck bro.

Parker
 

Faded

~SPONSOR~
Jan 7, 2003
842
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bclapham,

I'm interested to hear what you have to say once you start dinkin' with the carb on that '03 CR. :)

James,

00/01 Motor in the 02 chassis sounds like a good combo. If anyone has the resources it's you. Good luck if you decide to go through with it, you might start another trend where Service Honda sells 00/01 motors with PWKs to 02/03 owners to cure the jetting and the supposed lack of bottom end. ;)

ParkerCR,

Thanks for the support man! :yeehaw:
 

john stu

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Jan 7, 2002
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even though my bike ran good (after much jetting of course)like all of us i wanted it to run even better so i tryed the pwk form the carb parts wherehouse and the carb was susposed to be pre jetted for my bike (they asked my fuel, altude,mods)and told me they would pre jet the carb and that i would not have to change any jets but they would send some extras just in case.after fitting the carb on the bike (the pwk is bigger =tighter fit)the jetting they sent me was so far off the bike would not even run (with a new plug) it would start but run awfull you could not even take off and keep it running. i tryed cheking the floats (thinking it was stuck)and tryed the other jets sent with the carb ...no luck so put the stock carb back on and it ran good so i sent the carb back and they tryed to charge me all kinds of restocking fees + shipping .......ya i don't think so
 

Faded

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Jan 7, 2003
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Here's a bump to the top....any updates from anybody? Parker, did you get your dialed yet and if so what are you running?
 

Dragmeistr

Sponsoring Member
Oct 14, 2002
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Faded, how do you like that 265 kit? Worth the money? Its too hot to ride here in the summer so I was thinking of going that way along with porting. Suggestions?
P.S.
My Keihin still works great on my bike, even after the switch to Ultimate 2 and some minor jetting tweaks.
 

pace

Member
Nov 21, 2003
479
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FWIW.. I picked up a new '03 at the end of last season. My riding is all between 5,500ft and 6,000ft and I'm pretty much going off the recommended jetting for this elevation and temps, with a 390 main, -74 needle in the lowest position, and pilot 2 1/2 out. I premix our ****ty Colorado 91 octane oxygenated gas at 36:1 with Amsoil. The jetting seems crisp to me, but I'm not sure that my butt dyno is finely calibrated enough to be able to discern slightly rich or lean conditions. With the stock jetting in place when I purchased it, it was obviously insanely rich and would readily foul out. Leaning it out seemed to have the biggest effect on bottom end where the bike previously felt a little sluggish (not loading up though). It is now much more eager to lift the front wheel off idle, and the plug shows a pretty clean burn.

Then again, I've been riding a 125 for a long time so pretty much anything would feel torquey.

-Pace
 

CR69r

Member
Jun 1, 2003
21
0
i was getting the pinging even though i did have rich enough jetting. the plug i was using was causing this due to the fine wire getting prematurely hot. everything was perfect chocolate brown except for the tip of the electrode which was white. i tried a plug with the same heat range but a fatter wire -- BR8EVS--- no more ping.

i suggest trying this b4 the carb purchase and especially if u have the white tip on the fine wire plug u r using.
 

Borch297

Member
Jul 24, 2000
19
0
James,

I've been running the '01 Cr motor in a '02 chassis since '02. I love the setup, JMS Performance has done all the motor work (they did the Factory Connection team's 125 motors since '00). It has strong power from bottom up, definately does not have the hesitation/abrupt transition from low to mid as the new style motors.
Basically built new head stays, ran '01 radiators (for routing reasons), built new swingarm/cases spacers, and not too much else.

Good luck and have fun.
 
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