Description
This completely original 1969 Yamaha DS6 250 Scrambler is in truly beautiful condition. It's rare to find one like this. The Yamaha has Belgian papers and comes from a private collection.
The DS6's 246cc engine was a piston-port engine with a 56mm bore and 50mm stroke that had been around for 10 years. It was a true five-port engine, with the ports cast into the aluminum cylinders with cast iron sleeves. The '69 cylinders had three transfer ports as well as intake and exhaust ports, allowing a larger amount of fuel to enter the combustion chambers more quickly. The compression ratio was a reliable 7. 3:1, and the cylinders now had copper head gaskets, replacing the earlier aluminum gaskets that tended to fail under heavy stress. Of course, these new gaskets came from the racing TDs. Inside the engine were race-ready bearings, even though they would never be subjected to the over 10, 000 rpm that the TDs could reach. The touted 30 horsepower was quoted at 7, 500 rpm, and it was certainly taken from the crankshaft rather than the rear wheel. In road tests, only the "quoted horsepower" was mentioned.
Two 26mm Mikuni VMC two-stroke carburetors, in combination with Yamaha's Autolube system, directed the fuel-oil mixture into the crankcase. Yamaha was known for developing the Autolube system, where the oil was stored in a separate tank instead of mixing it with the gasoline in the tank. It was first used in Yamaha racing motorcycles in the late 1950s and then transferred to street machines in the early 1960s. The biggest advantage of Autolube was that the amount of oil mixed with the gasoline could be precisely regulated. Instead of a constant 20:1 mix, which could sometimes get quite smoky, the oil was dosed according to both engine speed and throttle opening. This could reduce oil supply at idle in the city but also deliver a powerful punch when the rider decided to go full throttle on a country road. The oil reserve was three liters, sufficient for half a dozen fill-ups of the 3-gallon tank.
Interested? Contact me. Tel./ Whatsapp the details below
Wiljan Feijen
VintageMotorcycles. nl
The motorcycle is located in Someren_Eind (NL), 40 km from Venlo. It is also possible to arrange a video call via Whatsapp 0031 6 295 637 46.
