I was eager to get the engine on the bench, so that I could take a peek inside. The last two-stroke engine that I had played with was a Bantam at 36 BHP/litre. The 250 LC engine manages some 140 BHP/Litre, so the intervening years between 1958 and 1980 must have seen some development. Despite this dramatic increase in output, the physical manifestations are few. Granted, there are reed valve inlets, tuned exhausts, and gaping ports everywhere, but mechanically the RD250 is, almost disappointingly, simple in construction. Within a few moments the single water-cooled head and separate barrels were off. Likewise the side covers. Still very Bantam-ish, the only unfamiliar territory was the drive side case containing oil and water pumps hidden beneath a plastic cover. Despite its high-tech pretensions, the oil pump simply squirts oil into a union at the side of each carburettor. Suzuki's CCI system, at least, managed to get the oil a little nearer the bearing surfaces.

In order to proceed further than this, I had to nip into town to get a flywheel puller (£4.50 from Mick Bull) and a 29mm socket to release the clutch centre nut. The lack of a clutch holding tool had me beat for a while, but eventually I just used a large 'G' cramp to lock the clutch plates, enabling me to knock the 29mm nut undone.

After the struggle to release the clutch and flywheel, the crankcases came undone, with only minimal effort, to reveal almost pristine innards. Despite its torture in the hands of countless boy-racers, the robust RD250's innards had survived unscathed. The crankshaft and gearbox both look like they are fit to survive for a good few miles yet.

After Scouring the adverts in Mechanics, I sent off several enquiries about Yamaha parts. Nearer to home, I remembered that Barrie Rodgers in Derby stock Yamahas, so I went in to ask about parts availability. After a gruelling 15 minutes with his microfiche viewer, David Gale had drawn up a list of footrest parts and other rubbers. The cost, at £47.50, took me back a little, but the little bag of parts all arrived within the week. Quite why Yamaha list their pillion footrests down to the last split pin escapes me. There is no number for the complete assembly, as far as I can see. I was expecting to see the Yamaha logo on the tiny split pins!

To help improve matters, I have now got hold of the parts microfiches from the helpful people at Mitsui Machinery Sales. I wish I hadn't given away my old viewer now.

Although previous owners had fitted many stainless bolts to the bike, I still had a large tubful of rusty steel clips, brackets and bolts at the end of my dismantling session. Yamaha chose to finish many of their fasteners with a chemical blacking process, probably to save a Yen or two. Unrestrained by such stringent financial control and in order to break up the matt black monotony, I will get all the bolts refinished with bright zinc.

Out came the rotary wire brush and all the little parts were cleaned up ready for the platers. A whole tubful of parts can be zinc plated for £15 or so, and it makes all the difference to the final appearance of a bike. Even on expertly painted bikes, eyes are immediately drawn to dull or rusty fasteners, more so than any other part.

In line with the matt black austerity that canny manufacturers managed to sell as the ultimate in 80's 'sportiness', there are few chrome plated parts on the 250LC. Only the rear brake operating arm, the headlamp rim and the foot pedals are allowed to shine out in glamorous chromium plate. I straightened out the pedals before taking them to Derby Plating services along with my tub of bolts for them to work their magic. The headlamp rim is in good nick, so that will just get a polish.

I felt a bit of a charlatan when it came to painting the engine cases. I repainted the silver Honda CB400 cases myself without any problems, but I wanted to be sure that Elsie's black covers had a durable finish. If silver paint chips, it is hard to detect. Not so with black ones. Anyway, it has been too cold for home spraying, lately, so Bill Woods at long Eaton Enamellers, blasted, etch primed and repainted the cases for me. When I called in he was getting ready to paint a brand new replica magnesium rear hub for a Manx Norton. That one hub was worth more than most of the bikes I have owned!

It is always a pleasure to visit local craftsmen & see what they are working on. Bill Woods always has something to see. When I went to collect the LC frame from Alwyn Smith, it was sitting alongside a Jota frame and swinging arm. I was tempted to do a swap. Maybe 'project Jota' next time......

Graham Curtis 4th November 2000

Mick Bull Motorcycles
Unit 2,
36 Canal Street
Derby DE1 2RJ
Tel 01332 367470

Derby Plating Services Ltd
148 Abbey Street
Derby
DE22 3SS
Tel 01332 382408