Jump to content
Sign in to follow this  

250X head identification?

Recommended Posts

I'm confused on this one, and have been searching the net for hours now, and I'm still confused.

I bought an 05 very cheep and as I tear into it, things are starting to not make sense. The head has no "smog" port near the exhaust. You can see where it's cast into the head, but not machined. So, I compare it to one of my two 250R heads. It's the same. I think one of the previous owners has already swapped heads.

So question one is: did all 250x's come with the smog system? Two: how can I determine what the head is? There are date castings on the front of the head, just below the valve cover. I also have a 450X but because the smog port is on the side of the head, I can't compare.

Share this post


Link to post
Share on other sites

check out this website, has lots of info you might like.

Here is a link to one of the pages, if you scroll down about half way you can see some cylinder head port changes between the different early years of the 250 X and R.

http://www.rickramsey.net/CRF250Xbigbore.htm

 

In 05 I dont think the smog device was being used yet, the california version of the 250X was detuned to conform to standards.

Share this post


Link to post
Share on other sites

Honda didn't start using the air injection port until 07.

 

I don't remember the part marking on the heads but the part numbers changed thru the years and a head should have some marks which will provide an ID.

 

The model code for the R is KRN, X is KSC.

The last part of the head part numbers are:

04 R KRN-A00

05 R KRN-730

06-07 R KRN-A00

08 R KRN-A10

09 R KRN-A30

10-11 R KRN-A40

12-13 R KRN-A60

14-15 R KRN-A80

04-06 X KSC-A00

07-15 X KSC-A10

Edited by Chuck.

Share this post


Link to post
Share on other sites

Thanks for the info guys. I guess my thoughts on there already being an R head on it have been shot down.

Now I'm debating on if I should swap in my 08 cam and springs or not. Or perhaps the entire 08 head. I like the reliability of the X and have considered just leaving well enough alone.

Share this post


Link to post
Share on other sites

The real question is: how will you ride it? I'm a notorious short-shifter and love the sound of a motor pulling hard at low rpm, so the X head and cam are my choice. However, if a screaming demon is your taste then the R parts are where it's at.

It's your birthday cake... Chocolate or vanilla is up to you.

  • Like 1

Share this post


Link to post
Share on other sites

 Help me to identify the model of the head from my 04 X. On the head apppears KRN code (is R code ?), on a friends bike  also  was 04 X It's same situation KRN code, he bought a new head from fastheads and the code now is KRNL. I ask you because i want to buy a stage II hotcam removed from R model and i don't know the year exactly, between 04-08. I'm in dilemma if will fit in my engine.

20160127_194003.jpg

20160129_173841.jpg

image1.JPG

image2.JPG

image3.JPG

Share this post


Link to post
Share on other sites

I'll put the link up again that shows some photos of the different year cylinder heads, its the only website I know of that documents with photos some of the differences, scroll down the page about halfway.

 

http://www.rickramsey.net/CRF250Xbigbore.htm

 

The head in the pic you posted looks like an early head to me either 06,05 or 04, and that cam is a stage one hotcam,

Share this post


Link to post
Share on other sites

Honda didn't start using the air injection port until 07.

 

I don't remember the part marking on the heads but the part numbers changed thru the years and a head should have some marks which will provide an ID.

 

The model code for the R is KRN, X is KSC.

The last part of the head part numbers are:

04 R KRN-A00

05 R KRN-730

06-07 R KRN-A00

08 R KRN-A10

09 R KRN-A30

10-11 R KRN-A40

12-13 R KRN-A60

14-15 R KRN-A80

04-06 X KSC-A00

07-15 X KSC-A10

 

Typo error on part numbers;  the 04-06 X head should be 12010-KRN-A00.

So the 04-06 X used the same head as the 04, 06 R. 

So KRN on a 04 X head would be OK.

 

The head part number for the X changed for 07+ and is 12010-KSC-A10.

 

What is interesting is Rick Ramsey's pictures of heads match an early data base of Honda part numbers that I have.  HOWEVER the current online Honda cross reference list (MRCycle) shows the same head for 04-07 Rs and 04-06 Xs. As Rick pointed out Honda supercedes newer designs for use on prior years, which for us creates a lot of confusion. IMO Rick's research is old enough to to be ahead of most of Honda's part number shuffles, and will provide a good way to identify original heads.

For me his website IS THE BEST reference for the X.

Share this post


Link to post
Share on other sites

It also helps to have purchased the printed parts catalog for each year as soon as it became available at Helm.  Printed catalogs can't be updated.....

 

I've got all the X and R parts catalogs lined up in the bookshelf.

Plus the Service Manuals and Owner's Manuals.

For each year.

 

What will I ever do with them when I lose interest in motorcycles and hang it up for good?🤣

 

 

Like that will ever happen.  :naughty:

 

:ride:

  • Like 1

Share this post


Link to post
Share on other sites

I'll put the link up again that shows some photos of the different year cylinder heads, its the only website I know of that documents with photos some of the differences, scroll down the page about halfway.

 

http://www.rickramsey.net/CRF250Xbigbore.htm

 

The head in the pic you posted looks like an early head to me either 06,05 or 04, and that cam is a stage one hotcam,

 Yes the head from the first picture is from my 04 X. If that cam is Stage one certain ? (because it's hard to identify exactly) will work fine with that KRN head, Athena 280 big bore, rejeting and a R exhast.

Edited by secbiker

Share this post


Link to post
Share on other sites

Yeah that is a stage one hotcam and will work with no problem, its a pretty good low and mid range cam and is not at all an extreme difference and also doesnt require any engine modifications. Depending on what jetting your currently using you might want to rejet but generally if youve done the basic mods like opening the air box and uncorking the exhaust along with the correct jetting your probably fine just dropping this cam in. Here is the link with details about the cam. Hope that helps.

 

http://www.hotcamsinc.com/ProductInfo.aspx?item_id=20

Share this post


Link to post
Share on other sites

The KRN is the Honda Product Code for the R, and early Xs used the early R head. In the absence of other marks that are similar to the last part of the part number e.g. A00, A10, A20, 730, etc you will need to use Rick's pictures to ID the heads. Because of Honda shipping latest heads to purchasers the current Honda part numbers don't help ID original heads.

 

I wish I had access to my 05 & 09 X heads so I could add some data to the discussion. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...