Beschreibung:

‘So good… you might call its creator a genius.’ – Motorcycle Sport. This quite remarkable machine is the product of one even more remarkable man - the legendary Fred Marsh - a dedicated enthusiast best remembered for his home-built, Moto Guzzi-inspired V8. A fitter and turner at the Harland & Wolff shipyard in Southampton, Fred Marsh had witnessed the MV Agusta and Gilera fours’ rise to dominance in the late 1940s/early 1950s and, in the absence of a response from the British motorcycle industry, set about creating his own version. Fred Marsh started design work on the four as early as 1953, though the machine would not reach running condition until 1962. With the exception of suitably modified Triumph Terrier cylinder heads, chosen partly because of their 75-degree valve angle that permitted the use of MV-type cams, all other parts were designed and made by Fred, including the necessary wooden patterns for all the major castings. Fred would often machine parts on his lathe at Harland & Wolff during meal breaks. However, much of the work was carried out on his own home-constructed lathe, which could be adapted for such tasks as line-boring the crankcase main bearing housings and also end-facing the castings. Convenience dictated the use of a proprietary gearbox, a Norton unit being chosen, and thus primary drive was by chain rather than the gears favoured by the Italian manufacturers. And rather than make his own frame Fred selected a Douglas Dragonfly chassis, chosen for its similarities to the Gilera unit, to which he fitted Norton Roadholder forks. In 1963 the Marsh Four was tested by David Dixon for Motor Cycle magazine but the engine would only rev to 7,200rpm; though by 1966, when the MR4 was tested by Robin Miller for Motor Cycle News, development had increased peak revs to 9,000. The Marsh Four was given race outings by riders including Tony Godfrey and George Collis but without achieving any significant results. Later in its life the MR4 was used on the road and displayed by Marsh on the Isle of Man during TT week, where Derek Minter tried it for size. In 1978 Fred Marsh died and the Four remained in storage until 1980 when it was purchased from his widow Connie by the current owner. The latter, a former British sidecar champion, had worked at Harland & Wolff in the 1950s and seen many of the engine parts being made on Fred’s lathe. The vendor commenced work on a full restoration, a process that took the next five years, and on completion the MR4 was featured in Classic Racer magazine (Winter 1985/6 edition, copy available). Various improvements have been made since acquisition including breather modifications to stop oil leakage, converting the valve operation from rockers to bucket tappets, plus carburettor changes to obtain better running. After initial outings it was found that the long-duration cam timing was to blame for the engine’s peaky power delivery and lack of flexibility. Its new owner’s first outing on a circuit was at the Motor 100 event at Silverstone. At this meeting John Surtees observed that the cam profiles for MV Agusta fours of the period were in fact quite mild. Subsequent checking with another well-known Southampton engineer, Len Harfield, revealed that the cams were not to the MV 125 profile as he had originally supplied to Fred Marsh. As a result of this conversation a ‘male and female’ toolmakers pattern of the true MV profile was borrowed from Len Harfield. After modification the cams were re-hardened and refitted, and it then proved possible to obtain timing figures similar to MV’s. At around this time the Amal GP carburettors were removed (expert opinion considered their ‘matchbox’ float chambers to be a handicap) and the original Amal 275 units refitted. These alterations gave the engine a fuller mid-range and good top-end power, while frame changes around the swinging arm and rear engine mountings have resulted in a truly fine-handling motorcycle, demonstrating that Fred Marsh chose cyc