1980 gsx1100 Compared to 1983 gsx engines.

[Danielson]

Can anybody tell me the difference in the engines. Are the parts interchangeable. Ie head. Barrels    Are the engine cases the same?  

[Arttu]

Main differences from top of my head:

• Flywheel taper on the crank is bigger on the later engines
• Naturally the flywheel is different too
• Valve cover has more bolts on the later engine so the cover and head are different
• Crank pins are welded from factory on later engines
• '83 engine has more and thinner clutch plates than older ones. Apparently all Katana engines use these thinner plates as well. Other clutch parts are essentially the same so both plate versions can be used on all models.

Otherwise the parts are interchangeable so you can mix cases, cranks, barrels, heads and so on pretty freely.