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Newer flat slide carb better than stock 250l carb?

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Anyone ran a newer non pumper carb with good results? Possibly a flat or "D" slide carb?

I have a few carbs laying around that may work on my bike "xr250l".

I believe they are smaller than the stock carb. But one of them appears that it will fit with minor modifications. It is a kehein "D" slide carb. I have a 1/4 turn throttle and cable that go with it.

I know it's speculation at this point. But is it worthwhile to try it out? Where to start with jetting?

Or am I wasting my time?

Btw what size is the stock carb.

I'm looking for better throttle response.

The light throttle pull, single cable, 1/4 turn and more compact design would be a bonus.

Would a smaller carb be a downgrade?

Or the fact that it is a newer design, and possibly more velocity be a plus.

Thanks

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From what I have found the stock carb is 30mm.

Pretty sure the one I Have is a kehein 28d.

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Mock up and test ride went better than expected. Even without the air box boot attached. "28D is shorter"

Throttle response quicker, smoother power delivery, light throttle pull is so nice!http://i1302.photobucket.com/albums/ag140/KillerK42/Mobile%20Uploads/th_WP_20151119_16_24_09_Pro_zpsan1xikag.mp4

Because of the promising results I am going to make a sleeve to attach the carb to the boot and install everything properly.

Not sure where to start on jetting. Carb came off a big valve klx110 with 150cc stroker. Didn't seem real far off. Plug reading won't be easy because it burns oil.

Any ideas on jetting?

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On my 230f,I use KX100 two stroke carb.28mm  D slide.Is that what you have.On our Xr300s 34mm flat slide carb.  I have spec on D slide,but its for Moded 230 motor.

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Yes 28d

What jetting are you running on your modded 230?

M jet 135/P jet 35/slide 2.0/needle JJL/ Needle jet(very important) Order from sudco they only have one size. Question how did you adapt.PWK carb to Xr250 intake manifold.?Bask of carb much smaller.

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Thanks for the reply!

Should give me a good starting point.

I had a snorkel tube that was the perfect I.d. And o.d. I cut it to length and it slips onto the carb perfectly and fits into the carb intake boot perfectly also. I plan on gluing it to the carb and using a small amount silicone on the od.

Right now it works fine with no glue or silicone. The glue and silicone will be an extra precaution.

I will take a picture when I get a chance.

Connecting to the airbox boot will be a little more tricky.

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Here is how I did mine.I had junk 96xr250 carb.  I cut back of carb off(Xr250) pressed it over outside,of PWK carb.With JB weld.Stock 230 carb is same outside as Xr250 carb.                                                                PTDC0196.JPG                    

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My setup is rubber. I may turn an adapter on the lathe if I'm happy with the performance.

I like the way you did it.

WP_20151123_16_39_23_Pro_zpswtavohtt.jpg

Carb is shorter and larger diameter on the airbox side.

What did you do there?

I have some ideas, but nothing finalized.

My jetting is 118main 50pilot 35slide and n68a needle from what I can see.

I will bump up the main.

Will I have issues with that needle and slide you think?

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On airbox adaptor.We have two shops in town that can make anything.I always try myself if possible.Here is what I did.Looked in my shop,for two pieces exhaust tubing.As you said Carb side to airbox too big and short.I found Mid pipe thin tubing for YZ450 fit carb.I was out of luck on,tubing to  fit airbox.I found perfect piece.The white car port tents,you buy at Coscos.That is thin wall tubing,and is tapered.Cut that welded the two up.Works perfect,also pressed fit to carb and JB weld.I hope your carb is not Chinese copy,they are junk. Even that PWK carb is 2mm smaller,should give more performence.I can not comment to jets your using.I would think Jets I use would be close.Your motor stock.Mine Moded. The 230 comes with 26mm carb,same body as Xr250 30mm carb.When I changed from stock carb,on my built 230.To pwk carb,to my surprise.The carb made more power then big bore,cam,header,procom box.More power everywhere,including off idle hit,screams on top.I hope you have same luck. BTR

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Thanks for the reply.

Carb is the real deal, not china copy.

From initial test ride it seemed better everywhere. So I have high hopes.

I may get it completed tonight. Not sure if I have a big enough main jet though.

If not I will pick up a couple tomorrow.

Thanks again.

Only reason I went with this carb is because I have it, and I haven't been using it.

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I stopped at the hardware store and found a tapered sleeve that should work. I will have to cut it to length.

I have a 135 jet also.

I hope to do some testing over the holiday. Weather permitting.

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30mm or 32mm LECTRON..................................  Enough said.  Next best thing to fuel injection and altitude compensating.

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Got everything together. Biggest issue was my throttle cable is borderline too short. With some creative routing I made it work.

I was able to ride it 8-10 miles. Unfortunately temps are freezing or below.

Test ride was initially disappointing. Off idle and midrange felt ok. Top end didn't seem to pull real hard. I found that quick acceleration felt good. Slow acceleration seemed flat, especially on top end at cruising speed.

After the bike warmed up I noticed idle and off idle was rich.

Pretty sure I'm rich everywhere. Especially on top.

I will have to do a plug check and go from there.

Im thinking down on main a little, dtop needle to 2nd position and adjust air screw.

I will report back.

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Got everything together. Biggest issue was my throttle cable is borderline too short. With some creative routing I made it work.

I was able to ride it 8-10 miles. Unfortunately temps are freezing or below.

Test ride was initially disappointing. Off idle and midrange felt ok. Top end didn't seem to pull real hard. I found that quick acceleration felt good. Slow acceleration seemed flat, especially on top end at cruising speed.

After the bike warmed up I noticed idle and off idle was rich.

Pretty sure I'm rich everywhere. Especially on top.

I will have to do a plug check and go from there.

Im thinking down on main a little, dtop needle to 2nd position and adjust air screw.

I will report back.

Im very surprised,with jets you have.That you got it to run at all.It is two stroke carb,with two stroke jets.I believe,you will need change.All parts in carb,like we did.Good luck.Keep us posted. I forgot my cable was too short.I have part numbers.For longer cable,and throttle if you need it.

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Im very surprised,with jets you have.That you got it to run at all.It is two stroke carb,with two stroke jets.I believe,you will need change.All parts in carb,like we did.Good luck.Keep us posted. I forgot my cable was too short.I have part numbers.For longer cable,and throttle if you need it.

You could be right.

I purchased it for my klx150 stroker. Supposedly with correct jetting for the stroker engine. It never did work right with that combination so I bought a Mikuni 26mm round.

It did however work good on a modded xr50 117stroker.

Hopefully it warms up enough to do some real testing.

I think if I drop the main that will fix the top end.

I do believe the needle will need to be changed.

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I was able to do more testing yesterday. Temps were in the 50s

I was able to do more testing yesterday. Temps were in the 50s

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