Update on progress with the MX250

Wheels

Took the tyres off the two sets of wheels, something that wasn’t exactly straightforward and didn’t think to heat the tyres up to help in removing them after 30 years on the bike. Took them down to Gerard Pettit down in Caerphilly who respoked the wheels in a couple of days. He used galvanised rather than stainless spokes for strength which seems fine by me.

Wheels and Tyres

Bought some medium compound Michelin motocross tyres from Paul at LG Racing and had the usual trouble in getting these on without destroying the inner tube. Need more lessons. Managed to polish the wheels a bit using Autosol and the ersatz dremmel bought from Argos.

Frame

Rather than getting it powder coated ( and if you do, can recommend Redditch Shotblasting ), decided to paint the frame myself. Used a couple of aerosol tins of Hammerite Satin black which seems to have given some excellent results.

Engine

Started to strip the engine (from the original bike) during a weekend of being duty officer at South Wales Caving Club and managed to look at the top end and remove the clutch.

SWCC workshop

However, the flywheel wouldn’t come off, partly as I don’t have the right puller (i have 15 others than don’t fit). Its a M20, 1.5mm pitch RH hollow puller and ended up ordering one from the US. Gavin and his lathe turned one up in brass (no steel rod available) and this was unfortunately strong enough to remove it, despite lots of heat. To be revisited.

IMG_0467.jpg

Clutch looks ok and the steel and fibre plates are greater than the wear minimum.

I also stripped the top end of the spares bike to see about the state of piston and barrel. Two hours of grunt and effort saw the ceased piston come out of the barrel, but not before I’d d broken one of the bottom fins off. Both piston/barrels seems to be at 1st oversize (0.25mm) which is good news.

I ordered some engine spares from Motolink , specifically some gaskets, bearings and crankcase seals. Also an oversize (0.5mm) piston kit, including piston, gudgeon pin, bearing and circlips.

Plastics and Decals

All the plastics and decals have arrived from the US and they were well packaged. Also shipped in such a way to avoid paying duty, which was nice. Managed to find the tank decals on ebay from Speed and Sport Yamaha . The plastics arrived via Reproduction Decals and all looked pretty good.

Forks

More on the fork rechroming and rebuild in a separate article .

Basically, the frame is ready to rebuild and start the process of getting back to a complete bike

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