I replaced the engine's 62t chainring sprocket to 72t. That lowered my total gear ratio from 32.46-24.82-21.96-19.09-16.23-14.32-12.41 and 10.5:1 in eighth gear...
to 37.08-28.37-25.09-21.82-18.55-16.36-14.1 and 12:1 in eighth gear.
The gears are closer in ratio now, with an extra gear between first and second gear. There is still a big gap between first and second, because first gear is the stump-pulling, up-the-ramp gear. Now, instead of using only five gears, I can shift down to sixth gear and still be pulling hard.
This is all theoretical, but I'll find out when I commute to work.
I took it for a test ride yesterday, but couldn't see a marked increase in performance yet. The first few gears might've been a bit snappier. I'm having issues with the drivetrain, due to this sprocket swap. I need to address these problems before doing a series of comprehensive testing.
The bicycle chain jumped off its 30t chainring sprocket, a mile into the test ride. I was doing 30 mph on flat ground. There have been some clunks and clanks coming from the bottom bracket area, more than likely due to the sprocket swap. I used new sections of 8mm(T8F) pocket bike chain to lengthen the engine drive chain. I MIGHT have reinstalled the 30t bicycle chainring sprocket bass-ackward. I don't remember which way the sprocket's "dish" was facing. Relying on memory, the bicycle chain is now a fraction of an inch inward. This is noticeable in 8th gear. I recall that the bicycle chain used to contact the outer edge of the front derailleur. Now it's maybe 1/8" inward, towards the front derailleur.
The sprockets will be removed & reinstalled today. Hopefully, that should clear all of the issues.
Honey, it's just a bicycle. and i REALLY need it to excercise, and to ride it to work.(hehe)