0078:
I ride very gently and get about 40 MPG. Like Whittlebeast said, keep the RPM very low. I have found the following: 1. A slip-on made no appreciable difference in my mileage; 2. A PCM will most likely make the mileage worse. The FZ1 is quite lean, and any leaner mixture will lead to surging and poor throttle response. 3. I expect the AIS would make no difference. 4. For easy riding, to get MPG, the stock air box is not restricting air flow. 5. There might be a tiny bit of improvement with a K&N air filter, however the price would take a llooooonnggg time to pay back. 6. I doubt irridium plugs would help. Ditto on the payback. 7. I tried some very high gears on my bike, using a smaller rear sprocket. For straight highway cruising, it improved the mileage from 40 to about 44 MPG, depending on speed. But in town with the high gearing, mileage got worse, due to the greater torque needed to accelerate the bike. Plus it kills the "fun factor" for the motorcycle. I think it is safe to say that any equipment mod will cost far more than the MPG benefit realized.
I am still puzzeled as to why the Gen I bikes can do better with carburetion than the Gen II with fuel injection. The camshaft duration, compression ratio, gearing, weight, etc. are extremely close to the same.
The best method is to go very gently on the throttle. Keep the RPM down below 3,500. Accelerate slowly. Be shifted into 6th gear by about 40 MPH. Let off the gas as early as possible when approaching a stop. The MPG is the only thing about the FZ1 that is at all disappointing to me. But the performance is superb and that is what the bike was designed for, which it does very well.