Manual says 5.4oz
mom
155-160 mL
About 16 US fl oz.
Use 10 ounces for each fork. Less if you want softer suspension, perhaps 8 ounces.
400cc (per fork) should be about average. The range is about 330cc to 425cc, depending on how stiff you want the forks to feel.
I know in 79" they were 1 down and 4 up.
Showa USD 45mm. Same as many 1992 Husqvarna WR's and the Suzuki RMX 250 circa '95
There's no governor on a Honda Nighthawk 250. A Honda 250 Nighthawk is a motorcycle, not a lawnmower.
330ml per fork
A part called a clutch fork pivot holds the clutch fork on a 1976 Ford F-250. Another part near the clutch fork is the clutch flywheel.
400ml
It states in the owners manual that fork oil level is measured with the forks collapsed, 120mm from the outer fork tube to the top of the oil. The inner push rod needs to be collapsed and bled by putting your finger on it and stroking it through the travel several times until it is full. Then you can measure the oil level accurately.