These motors, especially the 83's and 84's, were built for power out the driveshaft! The higher the rpm, the better the "running" ability of them. Gas mileage will actually be better without "lugging" the engine (as you have a lot of unburnt gas doing that) and performance if needed will be available at any time!
You must spend time adjusting yourself to this, experiment to find out exactly where your motor (rpm) is happy cruising at. If your increase in throttle comes very easy without any delay in corresponding rpm/speedometer rising together (easier to watch than feel), then you are becoming knowledgeable about the performance abilties of your powerplant.
Oh yeah, you might want to pick the front wheel up in first and second a few times to see how much is available! If'n I remember right from my 84, best powerband and fuel mileage came between 3800 and 4500 rpm's. This would be shifting up at 4500 and cruising around 3800.
However, if your young neighbor down the street thinks he can beat you (ask Muffinman!), these motors can easily go up to around 7900-8200 rpm's without floating the valves but horsepower starts to flatten out around 65-6900 rpm's. Remember, with the 1200's you've got the early editions of the V-Max motor buried in there! Makes riding a supposed "touring" bike a lot of fun if you want it!
Oh, another bit of advice, on the 83- 85-1/2"s, they had a "soft" split washer on the tranny output over at the middle gear end (left side of motor), it would wear enuff to allow 2nd gear to disengage itself under power input and "slip". There was a recall on this, and if it was done, I know they put a "mark" on the frame or motor somewhere down by the middle gear cover but don't remember exactly where/what it was. Maybe Dingy will jump in here to let you know.....