Cr250 Kehin Swap - Problem

JW381
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JW381
Has anyone done the Kehin Swap on a last Gen CR and had more issues than benefits? I did the swap about 3 years ago, for no other reason than because I read it enough times on here and Thumpertalk. I got a 2000 CR carb from JD Jetting for my 04. It had fitment issues for one, which I knew beforehand but was told it would be okay.

But beyond that, I had a lot of problems the entire time I had the PWK on.

Could it have been a faulty carb from JD or am I not the only one that didn't have positive results with the swap? I put the Mikuni back in and it runs great.
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809
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809 8/25/2016 4:52pm
8/25/2016 4:52pm
Did you do anything to it as far as tuning, float level etc? I will not be putting the mikuni back on my 03. It was quite an improvement for mine. I bought my PWK from Rocky Mountain and got some tuning advice from CamP on TT.
40
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40 8/25/2016 6:06pm
8/25/2016 6:06pm Edited Date/Time 8/25/2016 6:49pm
The 04-07 CR250 uses the short body PWK with TPS. These are usually retrofitted by swapping out from a late model RM, KX or YZ. There is a guy on TT who sells complete TPS wiring harness conversion kits to connect the retrofitted PWK's TPS to the 04-07 CR250 wiring.
The 2000 CR250 used a long body PWK without TPS. This carb is too long front to rear to fit well on the 04 CR250 and since the TPS is not available on this carb, the ignition will run in 2D mode. The 2000 PWK fits well on the 02 and 03 CR250 only.
I can not remember which slide the 2000 carb used, but we have had best results when using a #7 slide, and no leaner than #7.5 with a Yamaha needle- N3EJ for example. However, there are many needles which work well. Lots of guys like the Suzuki triple taper needles. The JD needles are also well regarded.
We tried the popular #8 slide but found exhaust gas temperatures got higher with a reduction in torque. Throttle response was a bit crisper with the #8 slide, but the torque trade off was not worth it in our case for the 04-07 CR250.

Honda11
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Honda11 8/25/2016 6:21pm
8/25/2016 6:21pm
I just bought a carb from JD Jetting last month for my 02. It fit perfectly, didn't have to change the cable like some of the other carbs being listed. It was a little tight fitting it into the boots, but once I got it in place it was fine. I didnt have to change anything on it, other than turning the air screw a quarter turn.
40
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40 8/25/2016 6:47pm
8/25/2016 6:47pm
Honda11 wrote:
I just bought a carb from JD Jetting last month for my 02. It fit perfectly, didn't have to change the cable like some of the...
I just bought a carb from JD Jetting last month for my 02. It fit perfectly, didn't have to change the cable like some of the other carbs being listed. It was a little tight fitting it into the boots, but once I got it in place it was fine. I didnt have to change anything on it, other than turning the air screw a quarter turn.
Yes, the long body PWK fits the 02 and 03 well.

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JW381
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JW381 8/25/2016 10:42pm
8/25/2016 10:42pm
I would be willing to chalk my issues up to the fitment, but Travis Hudson had an 04 with the 00 carb, and his worked fine. I think there was some kind of issue with the PWK I received from JD from the get-go. That, or my bike has some underlying problem. But, as I mentioned in my original post, I've replaced a lot of parts over the past 3 years (crank seals, clutch, clutch basket, top end, reeds, etc.) and the rich running motor always persisted with the PWK. Yesterday was my first day with the stock carb in 3 years and it ran pretty great. Not perfect, but great.
CamP
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CamP 8/26/2016 2:43pm
8/26/2016 2:43pm
The YZ250 carbs on my 05 and 07 CR250's work much better than the stock Mikunis. No way I would go back to the stock carbs.
JW381
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JW381 8/26/2016 7:30pm
8/26/2016 7:30pm
CamP wrote:
The YZ250 carbs on my 05 and 07 CR250's work much better than the stock Mikunis. No way I would go back to the stock carbs.
If I try the Kehin again, it will undoubtedly be a YZ carb. Its not outside the realm of possibility that I had other issues on my bike, but all I know is putting the TPS TMX back on was a big improvement over the JD PWK.
CrGuy2T
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CrGuy2T 8/27/2016 6:24am
8/27/2016 6:24am
Could be your jetting. I had to go to a fatter main on my pwk I got from JD. Not saying he sent me the wrong stuff or anything because I've used lots of his jet kits with success. Your jetting might be off a touch. But then again I have a friend that he swears by the stock carb with a JD jet kit. I guess different things work better for other people.
JW381
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JW381 8/27/2016 9:32am
8/27/2016 9:32am
CrGuy2T wrote:
Could be your jetting. I had to go to a fatter main on my pwk I got from JD. Not saying he sent me the wrong...
Could be your jetting. I had to go to a fatter main on my pwk I got from JD. Not saying he sent me the wrong stuff or anything because I've used lots of his jet kits with success. Your jetting might be off a touch. But then again I have a friend that he swears by the stock carb with a JD jet kit. I guess different things work better for other people.
My JD carb kept running rich. Right out of the box it wouldn't even run because it was drowning in fuel. Hd to turn the idle way up, lean out the needle, main. As I said in my original post, I didn't do the swap for any reason other than everyone saying to do so, meaning the bike ran fine before, I just wanted the benefits everyone was raving about. We'll see as time goes on.
CrGuy2T
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CrGuy2T 8/27/2016 12:01pm
8/27/2016 12:01pm
Where was the float set? If you get it right it's worth it. Sucks your having problems.
cable
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cable 8/29/2016 7:39pm
8/29/2016 7:39pm
I used one off a kx500. 39mm or 40mm. took it off when i sold the bike and put the mikuni back on. lol worked great.
Cancerman
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Cancerman 8/29/2016 11:46pm
8/29/2016 11:46pm
cable wrote:
I used one off a kx500. 39mm or 40mm. took it off when i sold the bike and put the mikuni back on. lol worked great.
Hang on to your KX500 39 PWK. I put one on my CR500 powered AF bike, it solved all my problems. Love it.

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