Yamaha YM1

The Yamaha YM1 is a motorcycle produced by Yamaha from 1964 to 1966. It used a 305 cc 2-stroke engine. It shared common parts with the 246 cc YDS3 and was virtually identical in all respects with the exception of bore and stroke.^[1]

The YM1 featured an oil-injection system that fed oil to the carburettor intake, the oil flow increasing as the throttle was opened. This gave the motorcycle sufficient lubrication for the crankshaft, cylinders, connecting rods, and pistons without requiring premixing of the oil and gas and with reduced use of oil.

Blue/white, red/white and black/white models were available for the YM1, which had a top speed of approximately 100 mph. The YM1 was an economical machine with high performance, being originally priced under $800 and capable of nearly 100mph, when such a speed was unusual for a small-capacity motorcycle.

References

^ Robert Smith (September–October 2006). "1965 Yamaha YM-1". Motorcycle Classics. Retrieved 2009-08-14.

Yamaha motorcycle timeline, 1950s–1960s

Type	1950s										1960s
Type	0	1	2	3	4	5	6	7	8	9	0	1	2	3	4	5	6	7	8	9
50											MF-1		MF-2			U5
50															YF-1					FS-1E
55															YJ-1	YJ-2
60																U6
75														YG-1		YGS-1
75																U7
90																H1	H3
90																AT90			HS1
100																		L2
125						YA-1		YA-2		YA-3		YA-5			YA-6			AS-1D
130						YB-1
175							YC-1
250								YD-1		YD-2		YD-3
250										YDS-1			YDS-2				YDS-3	DS5E		DS6
260									YE-1	YE-2		YE-3
260										YES-1			YES-2
305																YM1
350																		YR-1	YR-2	YR-3
650																				XS-1
125 Trail																				AT-1
175 Trail																				CT-1
250 Trail																			DT-1