Replacing the timing chain

04 crf250r,

I need to change the timing chain and I am wondering what I need to remove to get at it.

The cylinder head off already and the barrel can be slid back off in a second.

But do I need to pull the engine side cover? Magnetto? What is involved?

I do not have a book and I am not buying on for this kid. All of the top end rebuild procedures have been readily available online, but I can't find the cam chain replacement procedure anywhere.

Then again I am an idiot.

Any help is much appreciated gents

Pull the flywheel cover and flywheel.

special puller for the fly wheel im sure?

special puller for the fly wheel im sure?


I made my own flywheel puller. The local dealer had one but it was $45. YIKES.

I went to my local good auto parts store and bought a 24mm x1.0 axle nut for a nissan fwd car and a 3/4" grade8 nut and a 1/2" 13t grade 8 nut and a 4" grade 8 full thread bolt.

I welded the 24mm nut to a piece of 1" tubing I had that was cut to about 3" long. Make sure the ends are really square. On the other end the I welded the 3/4" nut topped by the 1/2" nut welded on that. The whole thing ends up about 4 1/2" long and you have to make sure that the top and bottom nuts are perfectly centered on each other so the bolt pushes straight thru the center.

The whole thing cost me $8 and was rewarding to build my own and it worked perfectly. I did use a short 10mm socket over the end of the crank to protect it from mushrooming.

Thanks for the help.


Just be careful you don't ruin the end of the crankshaft. That hole in the end of the crankshaft is the oil feed to the lower connecting rod bearing. If you damage it, it restricts or stops the oil flow and starves the bearing of oil. Then you'll be replacing the crankshaft and who knows what else.

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