crf 450 question

[midmich450]

what year heads and cylinders will fit an 04 crf 450 r?
i've been trying to get an new head and cylinder for my bike and have come across some advertised as 02 and 03 only then some as 02 to 08. hopefully someone can straighten this out for me.

 

[Matt90GT]

02-08 all swap

06+ has the best seat material. The 07-08 heads have the smaller exhuast valves, but still interchangeable back to 02

You can buy new heads with new SS valvetrain installed for like $550 ready to bolt on.

 

[midmich450]

thanks for the info. i'm looking to do this as cheap as possible as i don't have a lot of extra money so i probly won't get a new one. i've been looking at used ones on ebay in the 200 to 270 range. i plan on tearing it down and having it touched up at a local machine shop to make sure everything is good. on the 02 heads there is a hole for a manual decompressor, does this interfere with the automatic one my 04 has and if not is it plugged off?

 

[Matt90GT]

No not at all.

The cheapest route is to use the 04 TRX SS Intake valves and springs, and stock exhaust valves and springs (stock is SS). :

Intakes:

Valve, In 14711-HP1-670 2 each $ 20.19 = $ 40.38
Valve spring, In 14751-MEB-670 2 each $ 6.57 = $ 13.14
Valve Stem Seal 12209-KL4-005 2 each $ 4.82 = $ 9.64
Cotters, Int 14781-MEB-670 4 each $ 2.87 = $ 11.48
Retainer, In 14771-HP1-670 2 each $ 4.69 = $ 9.38

If you choose to reuse the exhaust valves, I would change these items at a minimum:

14782-MEB-670 2EA Ex SPRINGS $ 5.76
14772-MEB-670 2EA Ex RETAINERS $ 4.43
14781-MAT-000 4EA Ex COTTERS $ 2.18
12209-GB4-682 2EA Ex SEALS $ 4.06

Of course, changing the exhaust valves would be recommended. If you do them as well, you will need:

14721-MEB-670 2EA Ex Valves $ 32.82

or 2007 and later:

14721-MEN-A00 2EA EX Valves $ 31.99


Prices are not current, but give you an idea.

 

[midmich450]

thanks. i bought a used 05 head and it should be hear today. it will get sent off to a local shop and i will definately look into new valves,springs, so on.

 

[whenfoxforks-ruled]

Changing valves, make sure the seats get cut. Sure saves 1 big headache later. Vintage Bob