Make sure the hub's well oiled and clean the chain.

I think most 3-speeds were geared too high. They perk right up with a 20 or 22 tooth rear sprocket. You want to be able to do 60 to 90 rpm with the pedals. I don't know if high cadence is a modern thing or if people in the 70s were stronger bikers, but old bikes seem to be geared too high.

Your bike probably uses the same kind of sprocket which goes on most 3-speeds and coaster brake bikes. They're easy to install.

I don't know what these guys are thinking. Those bikes aren't that slow. Pardon me for saying so, but maybe you wouldn't like a road bike either, until you hop up your engine a bit.

They are kind of heavy, but that only matters when you're climbing a hill or accelerating. Accelerate gently.

If it's really a balloon-tire cruiser model, then I take it all back. I am talking about the 26x1-3/8 bikes.

The balloon tire cruisers seemed to come with rims which were too wide to put some narrower MTB road tires on.