The 1980 Harley-Davidson FLH was a large motorcycle for its time.
Increasing power on a 1980 Harley FLH Electra Glides is largely a matter of using available bolt-on parts commonly found in Harley performance catalogs. The traditional rules apply for building power: more air, more fuel, more exhaust. The 1980 FLH was a big motorcycle for its time, putting out 67 horsepower from 81 cubic inches of engine. Keeping up with today’s motorcycles, however, presents a bit of a problem for FLH enthusiasts.
1. Remove and replace the stock exhaust with a high-flowing performance exhaust. If you don’t want to contend with the additional noise, there are plenty of exhaust systems on the market that produce a more mellow, relaxed exhaust note while still providing the power benefits of an open exhaust.
2. Replace the stock air filter with a high-flow air filter. Although more expensive than traditional filters, they are also cleanable, so they can last quite literally for the life of your motorcycle.
3. Re-jet the carburetors. Older carburetor jets are much smaller and more inefficient than current jets. Purchasing and installing a carburetor jet kit for your FLH will let more air and fuel into the carburetor, allowing the engine to produce more power.