400ex timing chain ?

[jdubb]

How do you take the top sprocket off without the chain falling off the bottom? If anyone knows please explain in detail.. any help will be greatly appreciated!!!

[BLEEDRED]

You have to keep tension on the chain at all times. It is difficult. But I actually had my chain fall off the bottom sprocket and it wasn't too difficult to get back on. I did NOT have to remove the case cover.

I know this isn't detailed, but it's not a terribly detailed process. Just a good set of hands and have a buddy help. Then wire the chain out of the way. Good luck!!

[jdubb]

So how did you know it was still in time after removing the cam? How do you take the top sprocket off?

[BLEEDRED]

Let's see. At far as I remember is doesn't matter if you jump a tooth on the bottom. It's all about getting it right when you set it back up. There are lines on the cam sprocket. You have to line get the piston to top dead center and go from there. I don't remember the exact procedure, there is info. about it all over this site.

As far as the cam sprocket, just use an allen socket to break it free. Have a buddy hold back the motor with a wrench on the left side of the bike.

Are you changing the cam?

[jdubb]

No I gaulded my piston for the second time in 7 months.. Does anyone else have this problem? I paid $750 last time so I'm doing it myself this time.

[400exrider707]

Originally posted by jdubb
No I gaulded my piston for the second time in 7 months.. Does anyone else have this problem? I paid $750 last time so I'm doing it myself this time.

Your cam chain is probably stretched and jumping teeth causing valves to make contact with the piston.

I would get an 02 CRF cam chain... should be $30 shipped from service honda and its the same thing as the heavy duty ones that a lot of builders sell for $100.

I usually take a thin piece of wire and tie it to the chain and then to the frame, that way it cant go anywhere

another good idea to keep the sprocket aligned on the chain, zip ty them together so even if you unbolt it and take the tension off it stays on there.:macho

[jdubb]

Great...I haven't thought about that. CRF what? Thanks for the info. Can anyone help me with a service manual?


ALL HELP IS GREATLY APPRECIATED!!!

[GPracer2500]

Any year CRF450R and unless I'm mistaken, also the 06+ TRX450R.

[400exrider707]

Originally posted by GPracer2500
Any year CRF450R and unless I'm mistaken, also the 06+ TRX450R.

02 CRF 450 cam chain only!!!!

They changed the chains after 02, but Im not positive about before 02

[GPracer2500]

Originally posted by 400exrider707
02 CRF 450 cam chain only!!!!

They changed the chains after 02, but Im not positive about before 02

I just looked at the fiche. 02' - 07' CRF450R all use same cam chain: part number 14401-MEB-671. There was no pre-02' CRF450R. All the CRF450X's and the 06+ TRX450R/ER also use this same cam chain.

Am I missing something?

[jdubb]

:confused: I pulled the head and jug today, piston looks good. Crank is blue like it's been really hot around the rod bearing. Does it seem to yall like I spun a bearing? It lost all power as I was coming off the trn and then started knocking.

[400exrider707]

Originally posted by GPracer2500
I just looked at the fiche. 02' - 07' CRF450R all use same cam chain: part number 14401-MEB-671. There was no pre-02' CRF450R. All the CRF450X's and the 06+ TRX450R/ER also use this same cam chain.

Am I missing something?

hmm thats interesting... I know when I ordered mine it was crucial to get the 02 cam chain... and I do believe when I did order it they did have different part numbers... thanks for the info gp

[JOEX]

Originally posted by 400exrider707
hmm thats interesting... I know when I ordered mine it was crucial to get the 02 cam chain... and I do believe when I did order it they did have different part numbers... thanks for the info gp
A possible reason for different part numbers (and cost) for some parts that appear to be the same could be because of a change in location of manufacturing of the part.

I heard about this a year or so ago on the forums here but haven't confirmed it as being true.

If anyone could post some facts about this, that would be great:)

[lilpoppy]

I'm thinking about replacing my cam chain also, does anyone know if the 02 CRF chain will still work?

[sc400ex_rider]

ya 02 has 112 links , 05 has 114 they are different prices too?