2007 cr250 build

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4/29/2020 6:38 PM

A little over a year ago I acquired a 07 cr250 complete bike minus top end (cylinder/exhaust valve). I've found it really hard to find an exhaust valve shaft of all things therefore I can't finish the build. Would an 03 cylinder on the 07 bottom work (ecu/carb) or maybe just so an 02-04 exhaust valve on an 05-07 cylinder? PLEASE HELP

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4/29/2020 7:59 PM

You will need to run an 05-07 cyl. with those yr. exhaust valve. The 02-04 have 2 PV’s instead of 1 that the 05-07’s have.
If you end up running an 02-04 cyl., you will need to run those yr. pipes as well. The CDI would also be better to run if you end up with an 02-03 cyl.. The carb is not as crucial, but the 04-07 models did come with a shorter version Mikuni TMX with TPS which the CDI has a wire connection.

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Speak softly and carry a big stick.

4/29/2020 9:33 PM

H4L wrote:

You will need to run an 05-07 cyl. with those yr. exhaust valve. The 02-04 have 2 PV’s instead of 1 that the 05-07’s have.
If you end up running an 02-04 cyl., you will need to run those yr. pipes as well. The CDI would also be better to run if you end up with an 02-03 cyl.. The carb is not as crucial, but the 04-07 models did come with a shorter version Mikuni TMX with TPS which the CDI has a wire connection.

Thanks for clearing this up for me, really appreciate it! I was getting frustrated and thought about buying an 03 cylinder with exhaust valve included on Ebay..I'll just keep looking for the elusive exhaust valve that fits my bike

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4/30/2020 4:34 PM

I have been looking for that piece for about a year. I was thinking of having one made next top end rebuild. Mine has excessive wear and the PV rattles a bit.

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4/30/2020 6:56 PM

Hondas4Life3 wrote:

I have been looking for that piece for about a year. I was thinking of having one made next top end rebuild. Mine has excessive wear and the PV rattles a bit.

I emailed Denton Engineering asking if they produced or could produce one or a few I attached a few pictures of what it looked like. Stevie Denton replied and told me he's sure they could build them but would need one so they can measure dimensions. Would you be interested in sending them yours?

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5/1/2020 5:12 AM

kx450sr wrote:

I emailed Denton Engineering asking if they produced or could produce one or a few I attached a few pictures of what it looked like. Stevie Denton replied and told me he's sure they could build them but would need one so they can measure dimensions. Would you be interested in sending them yours?

I only worry about shipping it over seas. If it's lost in shipping we are now both in the same situation. Next top end ill try and find someone local.

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5/2/2020 8:38 AM

kx450sr wrote:

I emailed Denton Engineering asking if they produced or could produce one or a few I attached a few pictures of what it looked like. Stevie Denton replied and told me he's sure they could build them but would need one so they can measure dimensions. Would you be interested in sending them yours?

Assume you're referring to discontinued 05-07 Honda part: SHAFT, FLAP VALVE 14211-KSK-730.

Looking at the older 02-04 Honda part SHAFT A, FLAP VALVE 14211-KZ3-L20, you may be able to modify this part (which is still available) on a lathe or mill to get it to work on 05-07 cylinders. The overall design does not appear to be much different than the 05-07, and might be modifyable.
If you decide to have the discontinued part custom fabricated for you, or want to try modifying the 02-04 part and need measurements to copy from the 05-07, let us know. We'll take measurements and post them for you.

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5/2/2020 9:17 AM

40 wrote:

Assume you're referring to discontinued 05-07 Honda part: SHAFT, FLAP VALVE 14211-KSK-730.

Looking at the older 02-04 Honda part SHAFT A, FLAP VALVE 14211-KZ3-L20, you may be able to modify this part (which is still available) on a lathe or mill to get it to work on 05-07 cylinders. The overall design does not appear to be much different than the 05-07, and might be modifyable.
If you decide to have the discontinued part custom fabricated for you, or want to try modifying the 02-04 part and need measurements to copy from the 05-07, let us know. We'll take measurements and post them for you.

Thank you I really appreciate that! I'll take you up on your offer of taking measurements on an 05-07. I'll contact Denton Engineering and ask if they would rather work off an 02-04 and start from scratch.

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5/2/2020 10:21 AM

kx450sr wrote:

Thank you I really appreciate that! I'll take you up on your offer of taking measurements on an 05-07. I'll contact Denton Engineering and ask if they would rather work off an 02-04 and start from scratch.

Haven't heard of Denton Engineering & just did a quick search on them. If it's Phil Denton Engineering he is located in the UK. I'd recommend taking 40 up on his offer as he knows his stuff & is in the US..

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Speak softly and carry a big stick.

5/2/2020 1:37 PM
Edited Date/Time: 5/2/2020 1:40 PM

H4L wrote:

Haven't heard of Denton Engineering & just did a quick search on them. If it's Phil Denton Engineering he is located in the UK. I'd recommend taking 40 up on his offer as he knows his stuff & is in the US..

Denton is in the UK, you're exactly right.
Thats why we say, by the time he goes through the trouble of gathering measurements, then having Denton fabricate a new one, and then goes through the trouble of international shipping etc, etc, etc, he might just be better off fabricating a 05-07 shaft in the US, or possibly machining the older shaft to work..
No guarantees on the old shaft, and we don't have a 02-04 to compare to 05-07 in the shop. But it might be worth a try and could possibly save a lot of time.

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5/2/2020 2:28 PM

Yep. On all your key points above. Good to know you have the potential resources to try & fabricate something like this.
All be sure to put that in my memory bank in case I come across something like this myself. Thnxz..

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Speak softly and carry a big stick.

5/2/2020 4:57 PM

kx450sr wrote:

Thank you I really appreciate that! I'll take you up on your offer of taking measurements on an 05-07. I'll contact Denton Engineering and ask if they would rather work off an 02-04 and start from scratch.

H4L wrote:

Haven't heard of Denton Engineering & just did a quick search on them. If it's Phil Denton Engineering he is located in the UK. I'd recommend taking 40 up on his offer as he knows his stuff & is in the US..

40 wrote:

Denton is in the UK, you're exactly right.
Thats why we say, by the time he goes through the trouble of gathering measurements, then having Denton fabricate a new one, and then goes through the trouble of international shipping etc, etc, etc, he might just be better off fabricating a 05-07 shaft in the US, or possibly machining the older shaft to work..
No guarantees on the old shaft, and we don't have a 02-04 to compare to 05-07 in the shop. But it might be worth a try and could possibly save a lot of time.

I misunderstood you the first time but yeah for sure anyone stateside is way better across the board, any suggestions? I know Trick Engineering does machining and high quality work. I don't know why I didn't think of this before even reaching out to Denton Eng.

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5/3/2020 8:22 AM
Edited Date/Time: 5/3/2020 8:24 AM

kx450sr wrote:

I misunderstood you the first time but yeah for sure anyone stateside is way better across the board, any suggestions? I know Trick Engineering does machining and high quality work. I don't know why I didn't think of this before even reaching out to Denton Eng.

Maybe someone with a 02-04 shaft can post measurements? H4L or myself can easily supply you with 05-07 measurements. Then you can compare and decide with your machinist if it is even possible to modify to older shaft to work. Purchase a brand new older shaft directly from Honda and machine to fit. Probably the quickest and easiest solution.
Or, you can take the 05-07 measurements and just fabricate directly from scratch.

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5/3/2020 3:14 PM

40 wrote:

Maybe someone with a 02-04 shaft can post measurements? H4L or myself can easily supply you with 05-07 measurements. Then you can compare and decide with your machinist if it is even possible to modify to older shaft to work. Purchase a brand new older shaft directly from Honda and machine to fit. Probably the quickest and easiest solution.
Or, you can take the 05-07 measurements and just fabricate directly from scratch.

I'll take your offer of you supplying me with the measurements for your 05-07 shaft. Hopefully someone who has 02-04 can do the same. In the meanwhile I'll contact a machine shop and get quoted on fabbing one up from scratch. If it isn't scary expensive I'll just do that so I can continue with my build

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5/3/2020 5:22 PM

kx450sr wrote:

I'll take your offer of you supplying me with the measurements for your 05-07 shaft. Hopefully someone who has 02-04 can do the same. In the meanwhile I'll contact a machine shop and get quoted on fabbing one up from scratch. If it isn't scary expensive I'll just do that so I can continue with my build

Have an 03 cyl. apart right now. I’ll take some measurements of the PV shaft in the next day or 2 as time permits.

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Speak softly and carry a big stick.

5/4/2020 4:27 AM

I have a o2,can you show me the Pv shaft you are talking about ,will be looking at it later in the week,it’s disassembled at the moment!

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5/4/2020 5:34 AM

Try to contact motocrossgiant.com it says on there website it is available

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5/4/2020 6:15 PM

kx450sr wrote:

I'll take your offer of you supplying me with the measurements for your 05-07 shaft. Hopefully someone who has 02-04 can do the same. In the meanwhile I'll contact a machine shop and get quoted on fabbing one up from scratch. If it isn't scary expensive I'll just do that so I can continue with my build

Photo
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5/4/2020 6:24 PM

Photo
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5/4/2020 6:56 PM

40 wrote: Photo

Sweet! Thanks so much! I'll keep you all posted on how it goes and who to go thru in case more dudes have to go thru this like I had to

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5/4/2020 7:25 PM

Keep in mind that the square hex portion actually inserts into, and actuates the power valve. This places the square hex portion indirectly into hot exhaust gas contact. You will need to select a steel alloy that is able to resist exhaust temperatures. Using mild steel will most likely not be adequate.

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5/4/2020 9:42 PM

40 wrote: Photo

kx450sr wrote:

Sweet! Thanks so much! I'll keep you all posted on how it goes and who to go thru in case more dudes have to go thru this like I had to

Make sure you index the flats at both ends. I'm in the process of sourcing a supply of these.

I manufacture and sell parts like this for sport bikes, and when I found out these were no longer available, it was added to my list.

I'm currently restoring a 2006 CR250R, and this was the only part that was unavailable. My '06 doesn't need a new one, but if it was ever to break, I would be out of luck.

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5/4/2020 11:01 PM

Keep us all informed! How is it , I can still get most parts for my 1983 CR480 and this 2007 part is NLA??

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5/4/2020 11:11 PM

mxracer666 wrote:

Keep us all informed! How is it , I can still get most parts for my 1983 CR480 and this 2007 part is NLA??

I believe there are only 4 or 5 parts NLA for the 2005 - 2007 CR250. Not bad considering the bike is almost 14 years old.

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5/5/2020 7:26 AM

40 wrote: Photo

Are these two flats on the same plane? It looks like they could be clocked to a certain degree from one another. Photo

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5/5/2020 7:54 AM
Edited Date/Time: 5/5/2020 4:14 PM

The flat is sloped a few degrees from parallel to the square hex. The slope of the flat cut is equal on both sides- in other words the square hex can be installed into the powervalve North side up, or South side up and the flat will be in the same position with the same orientation for the cable guide to attach onto.
I'll try to get a more accurate measurement of the flat slope from parallel to the square hex.

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5/5/2020 8:13 AM

timobijnen84 wrote:

Try to contact motocrossgiant.com it says on there website it is available

It shows as in stock until you go to checkout. I tried motosport, RM, motocrossgiant, revzilla, ebay, craigslist, and offer up as sources. No luck

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5/5/2020 9:17 AM

40 wrote:

The flat is sloped a few degrees from parallel to the square hex. The slope of the flat cut is equal on both sides- in other words the square hex can be installed into the powervalve North side up, or South side up and the flat will be in the same position with the same orientation for the cable guide to attach onto.
I'll try to get a more accurate measurement of the flat slope from parallel to the square hex.

Clayton would rather have a power valve shaft so he can index it in his mill to see what degree it's at. Considering how critical it is he wouldn't want to make them and have them be incorrect. Message me if you'd be interested in lending yours for this we can work out a deal $

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5/5/2020 10:57 AM
Edited Date/Time: 5/5/2020 11:00 AM

I would not be surprised if you could get the 02-04 part to work. The front RC valve cable 14340-KZ3-L20 is the same for all years. The cable guide 14320-KZ3-L20 is the same for 03-07.. Since the cable guide 14320-KZ3-L20 is the same, there is a good chance that the shaft uses the same degree slope. The 02-04 part is a little different near the 6X1 thread end, but this area protrudes outside of the cylinder using the same cable guide anyway and could be easily adjusted on a lathe if necessary..
If we could get someone with the 02-04 part to post measurements it would be helpful.

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5/5/2020 11:27 AM

40 wrote:

I would not be surprised if you could get the 02-04 part to work. The front RC valve cable 14340-KZ3-L20 is the same for all years. The cable guide 14320-KZ3-L20 is the same for 03-07.. Since the cable guide 14320-KZ3-L20 is the same, there is a good chance that the shaft uses the same degree slope. The 02-04 part is a little different near the 6X1 thread end, but this area protrudes outside of the cylinder using the same cable guide anyway and could be easily adjusted on a lathe if necessary..
If we could get someone with the 02-04 part to post measurements it would be helpful.

Great point and I could find those on Ebay I can buy one and send it to him. Check back in a few

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