An already restored AJS owned by Peter Borthwick (photo: Peter Borthwick)
I’ve had the motorbike – an AJS 500cc single of about 1952 production – in storage and in bits for about 50 years. Calling it an ‘AJS 500’ is a bit misleading, as the engine number on the crankcase is for a 1953 Matchless 350 (same manufacturer – AMC, England). Other parts are also mismatched; it’s a bitser.
So, the most I can say for the reassembly is that I wanted the machine to be reasonably tidy; run well; and, at a superficial glance, look the part. Spending big on authentic parts and professional chrome plating would have to be avoided as much as possible.
Hence this series of articles on how I have managed to develop some quite good electroplating methods (I think) for the parts that are meant to be shiny, plus how I fixed other bits such as cooling fins, wheels, seat, and electricals.
First: the engine
Engine work came first; I wanted to see how it would run. It had been stored in a partially disassembled state – head off and out of frame. The aluminium alloy head was badly scored around the head bolt landings, but the valve seats and guides were fine; only a little valve grinding was needed. Happily, the valve guides gave my finger good suction as the valve stems were pulled out.
I made cardboard templates to match what the three missing bits of cooling fin probably were
The cardboard templates gave me the shapes to cut and grind from the cast-iron hotplate of an old barbecue; outside work to avoid fires from the sparks
The specialist that I took the head to – for planing and building up the
