I don’t have a Parts Book or Service Manual, just basic information. With a bore of 2-3/8" and a stroke of 2-1/2", your Fastwin has a piston displacement of 22.15 cubic inches. Like the "U" model Speeditwin, all main bearings are anti-friction. Its 14 horse power is developed at 4,500 RPM. The 130173 shear pin is a 1/4" diameter 17 St aluminum rod 1-7/16" long. The Standard B28AE propeller is a hollow two bladed Aluminum casting that acts as a water pump. A solid hub prop may not circulate enough water at slow speeds. In cases where overheating is a problem, enterprising mechanics have added an intake scoop below the exhaust outlet behind the propeller. Randy has such a device on his Junior Quad. The Champion O Com has been replaced by W-10 has been replaced by 510 . . . 🙂
