2000 YZ 250 rebuild

After racing for 17 years i got tired of all the service, washing bikes and traveling so i got hooked on windsurfing (motocross on water :-) and didn´t ride a dirt bike  for 6 years.

Last fall i took a trip to our local motocross track and my oldest son (4) was so exited and wanted to try, so i bought a 1982 pw50 and rebuilt it and gave it to him for christmas, he was so stoked!


So was i, and i suddenly got this urge to go motocross again.


I found my bike in a barn at a local farmer who had been racing it every fall and never done any maintenance the last 4 years...


Bought it for 1000$  and it was really in a bad shape.


So far i have rebuilt front forks, rear shock, linkage and swing arm bearings.

Will also change front- and rear wheel bearing, brakes, and a new top end.


The intake manifold was also rotten so that have to go.


Here are some pictures :-)


hel sykkel.jpg


ramme motor svingarm.jpg


ramme og motor.jpg




pw50 før.jpg


pw50 etter.jpg

How do i get the pictures big so you don´t have to click to se them full-size?

Edited by kimkt77

we have very similar stories. been about 7 years for me, my oldest is 7. just bought a pw50 for the 5 yr old, and a ttr50 for the 7 yr old. and a 99 yz250 for myself.


good luck with the build/project.


as for the pics. i use photo bucket for the forums. its free, you can edit photos and what not.

I have bought a new wiseco piston and are going to check the top end next weekend, bike sounded a bit high on idle, but i haven't checked it further. (just started it once with old petrol and a

rubber intake manifold that is cracked and rotten, so i will change this also.(maybe the reason to the high idle?)


The bike has a FMF fatty pipe and original rear exhaust. What kind of jetting should i have for this combo? I am really bad at jetting  :blush:

I will use it 150-300 m above sea level if that has anything to affect the jet-settings.

Had the top end removed to change piston this weekend, and found a cylinder that is toast...

It had some small scoring that caught my fingernail when checking. It looked almost ok, but i took it to a shop and they told me it was worn out. As far is i know it have only had 1 piston change, but the intake manifold was so cracked that it possibly got dirt in there.


Have to ship it of to replating, since there are no companies to do that here in norway i have to send it to holland, and it cost a fortune. My cheap bike is not so cheap anymore :-(


My question is; how much sideways play can i have in the rod? I can wiggle it about 5mm sideways and none up and down.


Here is also some pictures of the piston and crank, does it look ok? (The piston is going to be changed)








Finished at last! Got my cylinder back last week and went to the track yesterday.

First time on an mx bike or motorcycle in 7 years...


Just riding around trying to get the feel for the bike, slow and steady :-)




<iframe src="//player.vimeo.com/video/98406862" width="500" height="281" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>

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