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Mystery JAP motor
Chatting to Oz Ellison (one of our much younger enthusiasts) at Founders’ Day this year, the conversation drifted to a 250cc ohv JAP engine, which, along with a carburettor, BTH racing magneto and a four-speed Albion gearbox, was literally thrust on him two years ago.
An older neighbour was selling up and downsizing to a smaller house with a tiny garage to be near his daughter, thus the engine and accompaniments were placed by said neighbour in an old builder’s barrow and dumped on Oz’s drive. Why was Oz so lucky? Having passed his motorcycle tests about 20 years ago, he’s had a progression of modern machines, which have been joined by a couple of 1970s 750cc Japanese classics and, more recently, a BSA A10.
It makes total sense to me that the next step is the JAP engine and hopefully we’ll soon get him on proper motorcycles – ones with no gears or clutches and a belt linking the engine to the back wheel!
A couple of weeks later, Oz discovered more information about the engine’s past and supplied the full engine number.
It seems a relative of the donating neighbour had built it into a home-made spring frame for grass track racing sometime during the 1950s. The fact that on strip the engine was found to have a high domed piston with ‘extreme valve cutaways’ along with the presence of 600 main jet (dope sized
