THE BULTACO BUILD

It’s good to build up contacts in the motorcycle trade, and to keep useful motorcycle parts on the shelf, as you never know when you may require them.

Many years ago, when Bultaco ruled the trials world, Martin Lampkin had a special 370 long-stroke motor fitted in his factory Sherpa. It was a machine that never went into series production for the trials-buying public, most likely because Lampkin had an aggressive all-action style and the large-displacement 363cc motor was a fearsome beast to tame! I always wondered if it was a factory motor or one built especially for him by the Comerfords ‘spanner magician’ known as Reg May.

I also recall a big-bore Bultaco that appeared at the Scottish Motorcycle Show, in the MacLennan Galleries, in Glasgow around March 1979 that, at one time, had been in the capable hands of Mick Bowers. I never found out who built the motor for that machine either, but it quickly changed hands and went off the radar, never to be seen or heard of ever again.

Looking through some photographs got me thinking; what about building a 370 Sherpa? After all, it would be a pretty unique machine to have and to have some fun with!

I instigated a conversation with three-time

“Vesty’ is a passionate enthusiast for the Bultaco brand, and his knowledge is second to none; he willingly gave me some tips and pointers.”

World Champion, Yrjo Vesterinen, who I knew had built a 370 and attached a sidecar to it some years ago. ‘Vesty’ is a passionate enthusiast for the Bultaco brand, and his knowledge is second to none; he willingly gave me some tips and pointers.

I started by unearthing a 1977 model 199 frame that I had bought with other Bultaco parts some years ago from a Scottish trials rider Murdo MacPhail and sourced a long-stroke Alpina motor from the USA as it has the 64mm crank. A brand new Alpina 350 barrel and cylinder head came from InMotion in Surrey, a 199A swinging arm and other bits and pieces that I already had in stock were put to one side and marked up ‘370’ with a marker pen. The boys at InMotion also sourced a brand new Mahle 85mm piston for the project. The 85mm piston, coupled with a 64mm crank, gives an actual displacement of 363cc, similar to the Pursang and Frontera models, hence the ‘370’ moniker. It will breathe through a Dellorto PHBH28BS carburettor from Eurocarb coupled to a large-capacity air-box which I had sourced on eBay some time ago, fitted with the 340-style air filter. Soon I had all the necessary components to hand including an alloy tank, that was in quite good shape, which was despatched to Bike Paints in Fife who I have used for all my tank repairs and refinishing since 1994. They did not disappoint either, by producing an excellent finish with a design like that of Lampkin’s 1975 World Championship winning machine.

This is only the first part of the story. Coming soon, part two.