The 1100 has what is refered to as a wet clutch. The same oil that is used for the motor oil is used for the transmission. Because of this it is very important to use oil that is labeled "Wet Clutch Compatable". You can get this through your Honda dealer or motorcycle shop.
go to: www.goldwingdocs.com
Good idea to check the battery. Might need to be charged, or changed.
Water cooled.
Honda 10w40 works well
Follow the lower rad. hose. Its in there. Have to remove the rad.
21 psi
The standard comes with no extra equipment, fairing or side bags. The interstate is a full dress right from Honda.
To check most transmissions on Honda motor cycles you check engine oil. They have a liquid clutch that are in the crank case oil.
'79 is a 1000 cc , '80 is a 1100 cc. You would have to compare the both. Or check with the parts dealer.
Manual for the 1979-81 Honda Goldwing 1100 states "inlet 0.1mm, exhaust 0.13mm" hope that helps, bye.
It all depends on how you drive, but look at around 35 to 40 mpg.
This bike has an engine with a displacement of 1084.00 cc's or 66.15 cubic inches.