In this video, I will present you a motorcycle that has undergone almost no development in the last 50 years. It can be said that in this sense it is unique in the world.
I've never been a fan of Jawa, except for their speedway engines were the best in the days of fellow Kiwi's Ivan Mauger and Barry Briggs were world class speedway racers. Their street bikes always seemed a decade or two behind the rest of the manufacturers. They were never very popular in New Zealand, and I haven't seen one here for many years.
Many bikes have used that kind of frame, all the way back to the 1920ies... Norton got famous for its "Featherbed" frame, whitch was a doubbel closed loop frame.
A couple of corrections: The Jawa 350-634 was produced from 1973 (NOT 1974) until 1985, when it was replaced by the Jawa 350-638 model. I've owned a maroon frame 1973 Jawa 350-634-0, in the past. The 1973 and 1974 models don't have a semi-automatic clutch or a Posi Lube oil pump. The engine mounting plates have stamped indents and there is a curved metal bar between the saddle rails, instead of the later metal tube. The airbox was smaller and used the smaller CZ filter. Power output was only 22 HP @ 5,,250 RPM. The 1986 and 1987 Jawa 350-638 versions produced 34 HP @ 6,500 RPM and had a marked redline of 7,000 RPM. These were capable of 150 KPH and are referred to as "Full Power 638's". From 1988 onwards, all Jawa 350-638 models were restricted to 25 HP @ 5,500 RPM with exhaust gas choking collars on the baffles, shorter exhaust silencers and 2.5cm. narrower piston skirt openings, so that only 2 of the 4 cylinder transfer ports pre-charged when the piston was at top dead centre. For those with the knowledge, tools and skills, these engine power limiting restrictions can be removed, which many owners have done.
