Looking to upgrade timing chain etc.

[Blown 331]

I've got a 2003 400EX that is totally stock engine performance wise other than a Yosh slip on, still has the air box lid on too. I picked up the smallest Web cam from a friend and I'm getting ready to put that in.
My engine has a lot of rattle noise to it. Could be out of adjustment valves which will be taken care of when I do the cam. But my bet is a streched timing chain, I plan on doing the chain either way when I do the cam.
I bought a new 400ex in 03 but sold it the same year and got the first 04 450R from my dealer when they came out so I'm not much up on the 400 anymore but I beleive they do have timing chain problems.
I am wondering what is a good chain to get and do I need anything else? Tensioner, guides etc? Or is this stuff typically still good and I just need a new chain? Any other suggestions are welcome. Also once I do the cam and take off the air box lid what is a good main jet to start out with?

[Choppers]

get a crf450 chain. just like the hd chain but cheaper

[Blown 331]

The chain from a 450 dirt bike will fit the 400EX? Thats the first I heard of that, weird.

[hornetgod13]

Originally posted by Blown 331
The chain from a 450 dirt bike will fit the 400EX? Thats the first I heard of that, weird.

It's fairly common knowledge around this forum.

[m36indiana]

dont you need hardened rockers for a web cam

[Blown 331]

Originally posted by hornetgod13
It's fairly common knowledge around this forum.

Cool, thanks guys. This is the first I heard of it. Like I said I had a new 400ex back in 03 and just recently picked up another 03 so I'm not too up on them.

[400exrider707]

Originally posted by m36indiana
dont you need hardened rockers for a web cam


Yes you do. Web's are hardweld cams, and need hardfaced rockers, and if you put a hardweld cam in on stock rockers, it will eat up the rockers real quick.

Yes a CRF 450 cam chain is the same one all the motor builders sell as heavy duty 400ex cam chains. One can be bought directly from servicehonda or from C&D racing for around $30 or so, compared to the weak, stock 400ex chain at around $90.

[Blown 331]

Originally posted by 400exrider707
Yes you do. Web's are hardweld cams, and need hardfaced rockers, and if you put a hardweld cam in on stock rockers, it will eat up the rockers real quick.

Yes a CRF 450 cam chain is the same one all the motor builders sell as heavy duty 400ex cam chains. One can be bought directly from servicehonda or from C&D racing for around $30 or so, compared to the weak, stock 400ex chain at around $90.

Well crap, I don't have hard faced rockers. Anyone have the part number for the CRF chain?

[jeremy_283]

i ordered a heaby duty cam chain from four stroke tech

[leprogle85]

Any specific year of crf450 chain? or are they all the same?

[hornetgod13]

Call C&D racing at (402) 614-2508 and order one over the phone. I think they charged me $33.00. All you have to do is tell them you need a 400EX Heavy Duty Cam Chain. They'll know what to send you.

[WFO400]

Originally posted by leprogle85
Any specific year of crf450 chain? or are they all the same?

They are all the same part numbers, from 02 through 07 at least