Hi vitards sorry I'm blowing up build section with all my junk 😆. This is a build that's been on going since last year for my god father. Little story but gonna try to keep it short. He got back into racing with a pair of 03 yz250s and always had this parts bike in the corner of the garage that'd we take parts off to keep his other 2 bikes going. Throughout the years this thing would get robbed of its cdi box, wiring harness, inner clutch cover and lots of other parts throughout time. After few years he sells the other yz's and moves on to new ktm 350s but this sad thing just sat there in the corner of the garage. Before he got it I think it sat outside as well so it's rough. One day told him hey I'm taking this thing back to my house and let's build it back to a bike again. At the time I was parting out a 2016 yz250 and he bought my forks and shock from me with idea we're gonna use it on this 03 build. Fast foward a bit and now it's starting to be built. After a day of power washing and media blasting it started to look little better
Then came the crusty demons of dirt that is the motor. Mind you the cylinder has been getting mouse piss on it in corner of a garage for long time so that's gonna need to be sent out. Just hoping I can save the powervalve. But bottom ends apart and transmission looks great especially for a yamaha. No bent shift forks or chipped gears. So now gonna see what he wants to run for a crank/rod kit and piston and go from there. I know I'm gonna have to figure out a steering stop for the 06 triple clamp I have to work with the 03 frame and I'm gonna run newer front brake system. Anyone's that done this swap over I'd appreciate insight of what u ran into.
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That engine is ugly, but should clean up just fine!
I started with clamps from a 08 450 so some of my experience may not apply. I had to swap the stems. Also the brake caliper carrier was different and I needed a different axle ( longer probably. Idk) I ran the original stop for a few years but it’s not ideal. I can see how a crash could force it under the stop and you lose a lot of turning radius. I made a new stop out of 1/2” Steele. I made it go up the head tube an inch and a half or so. That way I had something to weld. The frame metal is thin there be careful.
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Frame is back from my powdercoater, think he nailed it. Today I ordered some parts for the bottom end. New wossner crank, pro x main bearings, cometic gasket kit and transmission bearing kit. After that gonna vapor blast the cases. So it's slowly coming together.
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