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School me on the 05 250 motor,,,please.

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I've made a few post's on my new to me 05 CR 250 with great result's, so thank you guy's. I've read so much info on this motor that I'm a bit intimidated to be honest. I know the carb is heading to the trash, that's a given,,,but,,, does the head/cylinder HAVE TO BE SHAVED for good result's ? I'm 52 year's old and don't need a ton of H P but I do want an engine built to be super dependable with good throttle response. I still ride MX and the ergo's are by far the best out of all the bike's I've ever owned. 

Edited by Alan48

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I can only speak for myself.  My 06 CR250 was pretty wild stock, not fun to ride.  Things I've done:

 

1.  the .030' base cut and head mod(work done by EG)

2.  yz pwk,

3.  Vforce3 reed

4.  9oz TMV flywheel weight.  

 

More recently I put a new stock head, and run 100LL.  I'm keeping the other head in case I need to switch to pump gas again for whatever reason.  

 

Jetting:  A715/294R Needle (OEM 2000CR250, 1/2 clip position leaner than stock A715/289R) 3rd clip, 45 pilot, 175 main, #7 Slide.  I'm very happy with the performance.  I'm getting fantastic throttle response from bottom to top.  Power everywhere.  Trackable and controllable!  I also just put a new DEP pipe on, but haven't had a chance to ride with it yet other than a test run making noise in the neighborhood.  Felt and sounded good.

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I've made a few post's on my new to me 05 CR 250 with great result's, so thank you guy's. I've read so much info on this motor that I'm a bit intimidated to be honest. I know the carb is heading to the trash, that's a given,,,but,,, does the head/cylinder HAVE TO BE SHAVED for good result's ? I'm 52 year's old and don't need a ton of H P but I do want an engine built to be super dependable with good throttle response. I still ride MX and the ergo's are by far the best out of all the bike's I've ever owned. 

 

I think if you are wanting a good smooth power delivery on the 05-07 cr250's shaving the base of the cylinder is a great place to start.  Check out this thread it has a wealth of info in it.

 

http://www.thumpertalk.com/topic/941288-new-07-cr250/page-1?hl=+new +07 +cr250

Edited by frdbtr

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I think if you are wanting a good smooth power delivery on the 05-07 cr250's shaving the base of the cylinder is a great place to start.  Check out this thread it has a wealth of info in it.

 

http://www.thumpertalk.com/topic/941288-new-07-cr250/page-1?hl=+new +07 +cr250

I'm glad you found and brought this to my attention, my computer is so old there's time's it wont let me use the SEARCH box.Time for a new computer,,,thank's frdbtr.

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I think if you are wanting a good smooth power delivery on the 05-07 cr250's shaving the base of the cylinder is a great place to start.  Check out this thread it has a wealth of info in it.

 

http://www.thumpertalk.com/topic/941288-new-07-cr250/page-1?hl=+new +07 +cr250

 

+1

I believe a lot of folks have benefited from Cam's thread.  I know I have.  Thanks Cam for all the good info!

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I'm glad you found and brought this to my attention, my computer is so old there's time's it wont let me use the SEARCH box.Time for a new computer,,,thank's frdbtr.

 

CamP just shaves the base of his cylinder in his thread, then gets a PWK carb from a 00 YZ250 and uses a CEJ needle for his jetting.  He has a great combination(I have tested the CEJ needle and it is a really good needle for this bike).  I decided to run pump premium fuel in my 06 so I had Eric gorr shape the head for pump premium along with the cylinder shaving and that has turned out to be an awesome combination for me and it only cost me $100 plus shipping to have the work done.  I have since added a 10oz flywheel weight, I have not had the opportunity to check how the bike responds on tight trails with the flywheel weight yet but the last ride I went on without it the bike responded beautifully when I needed it to go slow and use its low end grunt.  I don't have any experience with any other CR250 motors but I love this one, I will never sell this bike.

Edited by frdbtr

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+1

I believe a lot of folks have benefited from Cam's thread.  I know I have.  Thanks Cam for all the good info!

This is why I'm up so late !!  This is exactly the info I need and I want to say a huge THANK YOU to you guy's, TT and Camp !!  Camp, if you read this,,,,well,,,,may the moto-god bless you, your knowledge is honorable.

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http://www.thumpertalk.com/topic/1013742-keihin-pwk-airstriker-yz250-to-cr250-“starter-kit”-w-harness/#!Hca31

 

Here's another good link to look at for making or getting a adapter wire harness for the pwk.  I ordered the parts from easternbeaver.com and made my own, but would have been cheaper and easier to order one of HondaMXracer's

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CamP just shaves the base of his cylinder in his thread, then gets a PWK carb from a 00 YZ250 and uses a CEJ needle for his jetting.  He has a great combination(I have tested the CEJ needle and it is a really good needle for this bike).  I decided to run pump premium fuel in my 06 so I had Eric gorr shape the head for pump premium along with the cylinder shaving and that has turned out to be an awesome combination for me and it only cost me $100 plus shipping to have the work done.  I have since added a 10oz flywheel weight, I have not had the opportunity to check how the bike responds on tight trails with the flywheel weight yet but the last ride I went on without it the bike responded beautifully when I needed it to go slow and use its low end grunt.  I don't have any experience with any other CR250 motors but I love this one, I will never sell this bike.

Good to hear, and I'm pulling this motor in a few day's to send the good's to EG.This bike is gonna be a keeper also, she's getting an extreme make-over due to excessive neglect. I'll post some pic's soon, but be warned and have a crying towel handy, seriously,it's bad !!,,,,and It's late and I'm out for night, thank's again. A48. 

Edited by Alan48

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,,, does the head/cylinder HAVE TO BE SHAVED for good result's ? I'm 52 year's old and don't need a ton of H P but I do want an engine built to be super dependable with good throttle response. I still ride MX and the ergo's are by far the best out of all the bike's I've ever owned. 

I would say Honda should have done this mod before the engine left the factory but then these bikes would be harder than ever to find.

Join the 30 Off club for sure. The power delivery to the ground is amazing and so predictable it’s like a totally different bike.

I previously had the Mo-better porting on this cylinder but did not have favorable results this mod gave me.

I just got the cylinder/head back from EG and I put "WOW!" in my jetting notes

I'll be 57 soon so you're just a young buck, Isn’t that right George :thumbsup:

Edited by AXAxiom
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I would say Honda should have done this mod before the engine left the factory but then these bikes would be harder than ever to find.

Join the 30 Off club for sure. The power delivery to the ground is amazing and so predictable it’s like a totally different bike.

I previously had the Mo-better porting on this cylinder but did not have favorable results this mod gave me.

I just got the cylinder/head back from EG and I put "WOW!" in my jetting notes

I'll be 57 soon so you're just a young buck, Isn’t that right George :thumbsup:

 

+1 If Honda had sold the bike with a power delivery similar to what the bike has after the cylinder and head mods, along with a PWK carb, it would have dominated every shootout and, you are right, would be impossible to buy used.  I am glad I got mine though.  I never thought I would love riding a bike more than my 05 450, but this one is more fun. 

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I would say Honda should have done this mod before the engine left the factory but then these bikes would be harder than ever to find.

Join the 30 Off club for sure. The power delivery to the ground is amazing and so predictable it’s like a totally different bike.

I previously had the Mo-better porting on this cylinder but did not have favorable results this mod gave me.

I just got the cylinder/head back from EG and I put "WOW!" in my jetting notes

I'll be 57 soon so you're just a young buck, Isn’t that right George :thumbsup:

I like the WOW factor added in, that boost's my confidence in rebuilding the motor,,, and being called a young buck,,,,I'll take it !!  I pray I'm still riding at 57, I'm fairly banged up now and could use a new set of knee's.  thank's AXA. :thumbsup:

Edited by Alan48

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