you apply oil to the suspension area and then push it up and down to work the oil in.
440 cc
300 ml
qt fork oil and type oil for the front fork on each side
120mm level
the front fork oil leval is to be set at 130mm from the top of the fork (air gap)..with the fork spring out ..and the fork fully collapsed ....
fork oil amounts for a Yamaha GT 80 are 108 to 116cc's per fork tube. you should use 10w motorcycle fork oil. this is good for all years from 1974 to 1980.
Each front fork holds: 400cm3 or 14.1 oz or 13.5 US oz.
I like 13 to15psi
At the bottom of each fork there is a hex head bolt, metric I think # 8 Be careful not to strip it.
7.8 oz. of 10wt fork oil
The bike has a front fork oil of 10w.And the manual prescribes of upto 251ml of oil for each fork.
238ml per fork