250-500cc WR250 / 300 Keihin brass; What's in yours?

For those of you who have switched over to the 38mm Keihin A.S., what brass are you running?

Mine is set up with: 42 / 178, CEK-4 / #7 slide.

I'm considering trying some Yamaha needles, since I've had good luck with them when I swapped my Honda CR250's over to the Keihins. They are a dual taper needles and seem to work pretty good.

I also thought about trying some of the JD needles. I think he's got a kit that has some generic Keihin needles that might be the way to go.

'07 WR 250 and I was running in the winter a 180/48/DDJ 4th with a #7 slide.


I now have a 175/45 or 42.5/DDJ 3rd with a #7 slide but I have not ridden it yet in the warm weather. I hope to ride it this weekend. Been riding a 4 stroke and I am excited to take the WR out again. I have a few Honda needles and just have not tried them yet. The numbers are kind of weird.

There are good cross references to the Honda needles on the CPW website. They are pretty much the same needles with a different numbering system.

Your jetting should be considerable richer that what's in my bike, but that's what was in it when I got it. Mine seems like it might be a little lean on the bottom, but I haven't got to really ride it yet.

Seems I've heard a lot of DDJ and DEK needles used in the WR's. That's why I'm somewhat concerned about this CEK.

To be honest that is why I am running the DDJ needle from reading about others with good results. Not that I think it is the best. I rode it around the house with a fresh air filter and it seemed smokey but will find out Sunday. I am usually a little more happy with the bike a little fat for the transition to mid for where I ride. It is supposed to be like 95 degrees on Sunday and humid, I am at around 900 feet alt. Do you have OFG's WR?

Yes, I bought OFG's WR. It was pretty well roached.

I just wonder if the guy who are running the DDJ's are running them because that's what comes standard in the carb, or because it works the best?

What bike came standard with a DDJ or triple tapered needle? I got my carb from my friend's Honda dealership and it came with the 7 slide. Had to order the needle. OFG liked to ride but it's hard to kill a WR 250. I am thinking of selling my WR but it is so hard getting rid of such a great bike.

The 38 comes with a DDJ standard when you buy them from an aftermarket supplier, i.e. CPW.

I'm not sure who has triple taper needles? Are JD needles triple taper, or dual?

My 42 / 178, CEK-4 / #7 slide brass combo is pretty decent. Low RPM operation is really good. Coming on the needle seems a little sharp, for my taste, and has a pretty short span.

Or, it's got a pretty good hit, then signs off early. That's probable what the mag guys would say.

I may go with a "J" diameter to see what it's like. I'd just like to smooth the transition from low to mid / top. But, overall it seems very effective.

I think I can pull some decent race results the way it is. Especially if it's a gnarly course. This thing is a mountain goat.

So are the 38mm PWK Air Striker carbs the same? I have seen one on ebay advertised for a Honda 250. Was wondering if this would work and then just get a jet kit to lean it out for the altitude.

Yeah, it's pretty much the same, I'm sure it's the standard issue PWK. It will just come with a DDJ needle and something like a 50 pilot, 175 main and #7 slide.

Thanks for the info. Haven't given up on the Mikuni yet, but I'm waffling

One thing I forgot to ask about the Keihin...is it pretty much the same width as the Mikuni TMX 38?

edit: I did some searching and from what I'm finding, the Keihin is 15 mm wider than the TMX. I already find the TMX a tight fit between the boots.

Those numbers you find on the web don't jive with what we have. The stock carb is 85mm front to back, not 75mm as you probable found. And I'm not sure the PWK is actually 91mm, I'll have to meassure it when I have it out, but it seems closer to the 85mm.

Everybody swaps and I've heard of no problems.

Just to let you guys know, I've been playing with some JD needles with very good results. I'll post more when I feel like I've got it nailed down.

I'm liking the JD blue needle, single ring in the 4th groove, 42 pilot 2 1/4 turns on A.S., 182 main. I was running a 178 and was getting some ping just past 1/2 throttle, so I went up to the 182 and it actually seems to pull better on top.

Found something that might be of interest; I tried a N3VE-3rd needle from a '99 Yamaha YZ250 with a 48 pilot, 175 main today and really like it. Seems happier to pull a gear high and torque through rough sections and then transitions to the top end better. Less hit.

I think I'm going hang with this for a while.

I've been running DDK 2nd from top178 and 45.Now that the weather is cooler 50% I have not ridden it but warmer temps it seemed just a tad rich on bottom.32-1 premix and the head has been cut.Try'd cek,dek and did not care for either,to lean.
Terry

I did the 45 pilot / 178 main and JD blue 3 after post #15, but it still didn't like to start so well.

With the 48 it starts good and seems to like pulling a gear high better. A little strong low end torque, I guess.

The main thing is it does the dead engine starts better and I can pull holeshots again.

I plan to try the next smaller diameter with a 45 main though, just see what it's like.

Anyone got some jetting specs for the WR360 with a PWK air striker 38mm???

Can't say 100% for sure, but the specs should be fairly close for the 360, too. The bigger volume of the cylinder will pull more air through the carb at a higher velocity creating a stronger signal at the jets, so they end up pulling more fuel.

Ever notice how a 125 with the same carb as a 250 will tend to have bigger jets?