04 CRF250 Top End. Replace the cam chain too?

[snb73]

I'm doing a topend on my son's 04 CRF250. Instead of having the guides replaced and seats ground, I bought a new head from Service Honda.

I ordered; a new head, valves, springs, valve spring retainer, cotter vavles, piston, rings and a cam chain.

I am the second owner and this is the first top end. Should I replace the cam chain or reuse the original one?

Thanks, Steve.

 

[nikki]

We replaced the cam chain in my '03 YZ 250F (which I owned for 3.5 years) around the 2 year mark, just for general preventative maintenance. Recommended by DRN's engine guru Rich Rohrich. For $30, it's worth it for the piece of mind, as I have heard they can stretch/wear out, just like any other chain. It was pretty easy to replace, once we figured it out. You did have to pull the flywheel (maybe stator too?) if I remember right to get to the bottom holder. In the 2 years I owned it, I think I did rings after 1 year, and a full top end and cam chain at 2 years, and another ring job around 3 years. One set of clutch plates a year too. Valves never moved from new. :cool:

 

[jason33]

wow how much did the head assembly set you back???- i would suggest a new chain
i mean if you put that much in, you might as well use a new chain too

 

[MikeS]

Get a new cam chain tensioner or a manual one, they get weak fast on the CRF250.

 

[snb73]

This is from Service Honda. I priced new guides/seals/seats from a rebuilder for $300. It seemed more cost effective to purchase a new head.


Part Number Qty Description Price

14711-KRN-670 2 VALVE, IN. $ 79.54
14721-KRN-670 2 VALVE, EX. $ 53.18
14751-KRN-670 2 SPRING, IN. VALVE $ 7.06
14761-KRN-670 2 SPRING, EX. VALVE $ 8.42
14781-MAT-000 8 COTTER, VALVE $ 17.2
12209-GB4-681 4 SEAL, VALVE STEM $ 15.64
14401-KRN-671 1 CHAIN, CAM $ 29.67
12010-KRN-670 1 CYLINDER HEAD ASSY. $ 227.07
14771-KRN-670 4 RETAINER, VLV SPR $ 18.2

Total (Excluding Taxes and Shipping) $ 455.98

 

[Rich Rohrich]

Get a new cam chain tensioner or a manual one, they get weak fast on the CRF250.

I'll second that. On the Hondas (250 & 450) replacing the cam chain tensioner once a year is critical.