From Cycle World. August 1976.
Yamaha’s secret flat track engine: How and why.

The Story of O … OW72
A nice story. No secrets. Kinda sad.
From Cycle World. August 1976.
Yamaha’s secret flat track engine: How and why.
The Story of O … OW72
A nice story. No secrets. Kinda sad.
This manual first appeared in 1972. Here is the 1973 revised edition. Includes Section 11. XS750(650) Racing Special.
The OW72 motor was developed to take this and the then relevant associated tuning knowledge to another level.
Racing Part numbers referenced in this are found in the Yamaha Racing Parts Book.
Yamaha Racing Tips … mostly for the 2 stroke program … includes Section 11 XS750(650) Racing Special
YRT contents
YRT contents
YRT warning
Here are the sections. Relevant to XS650s are Sections 1 and 11 …