Additional information
by Floyd Clymer (Author), Velocepress (Producer)
108 pages and more than 120 illustrations and charts, size 8.25 x 10.75 inches. This manual covers the overhaul and maintenance of the engines that were installed in the 1972 to 1978 Penton-KTM series of off-road motorcycles. In addition, it also includes an illustrated parts manual for those same engines.
From 1972 onwards the majority of Penton motorcycles utilized KTM engines. The most recognizable early Penton-KTM machines were the 175cc Jackpiner, the 250cc Hare Scrambler and the 400cc Mint. In 1976 the Penton-KTM MC-5 and Cross-Country models were introduced followed by the GS-6 in 1977, all available with 125cc, 175cc, 250cc and 400cc engine options. This manual is a compilation of the April 1979 KTM 'Engine Repair Instructions' and the May 1977 'Parts Manual'. It should be noted that KTM identifies their 1972 to 1979 series of engines by 'Type' numbers and the engines covered in this manual are the 125cc Type 51 (1975-1976), 175cc Type 52 (1972-1979), 250cc Type 54 (1973-1979) and 400cc Type 55 (1974-1978).A BRIEF EXPLANATION OF THE ASSOCIATION BETWEEN PENTON AND KTMIn 1967 when John Penton approached KTM (Austria) with a plan to manufacture off-road motorcycles to his design, it was obviously seen as an opportunity by KTM to gain a foothold in the expanding USA off-road motorcycle market. Certainly, having someone like John Penton representing their product was a major win for KTM, as John's prominent status in off-road racing was already well established. The first of the Penton-KTM joint venture motorcycles, the 'Berkshire 100' and 'Six Day 125' models, powered by Sachs* engines arrived in the USA in 1968. The use of a Sachs powertrain was an obvious choice for KTM who, without any in-house engine capability, had been using Sachs engines in their moped, scooter and road-going motorcycles since the early 1950's. While the Sachs powered off-road machines established a solid foothold for Penton motorcycles, John began to pressure KTM to construct an engine of their own design. The first of the Penton models powered by KTM engines debuted in 1972 as the '175cc Jackpiner' followed in 1973 by the '250cc Hare' and the '400cc Mint' in 1974. These Penton-KTM powered models are covered in Workshop Manual ISBN 9781588503077. (*For Sachs powered Pentons see Workshop Manual ISBN 9781588502933).However, KTM was also marketing identical KTM badged bikes as MC (Motocross) and GS (Gelande Sport) models on an international level. Obviously, this did not sit well with John and the situation worsened when those same KTM badged bikes, began to show up on the west coast through a different USA importer.The 1976 'MC-5' and 'Cross Country' and the 1977 'GS-6' Pentons were also badged and sold as KTM's and the association between John and KTM continued to deteriorate. In the interim, KTM had been pressuring John to relinquish control of his distribution rights and in 1978 KTM purchased both the distribution rights and the company infrastructure and the Penton brand was no more. A sad end to an era of great innovation by John Penton, however, his motorcycles and the identical KTM versions are regarded as some of the best ever to come out of the 1970's off-road motorcycle phenomenon and are highly collectible and still used in vintage events by enthusiasts worldwide.
