The 9-78 is probably the actual month and year the bike was built. The model year which is 1979 has nothing to do with the actual date built but it has to do with model year for which it was built.
fuel line routing on 1979 Yamaha xs1100
95 hp
$2300
34 mm Mikuni CV Carbs Qty-4
Cylinders- on the motor from left to right...1,2,3,4. Firing order is 1,4,2,3. Clymer manuel.
2Y9 Prefix on the Yamaha DT 400 frame and Engine No: is the 1979 Model that shipped to Canada and South Africa. Also known as the DT400F. It's most common colour was Competition Yellow for 1979
1979
the motor 2x8-000880 is a 1979 IT 400 Yamaha
The cast of Freeze Frame - 1979 includes: Paul Julian as Road Runner
.032
Freeze Frame - cartoon - was created in 1979.
1979 XS1100 S Front tire 100/90 19 or 110/90 19 Rear tire 130/90 16 Stock or 140/90 16 DunlopE3 Black wall only