750-1000 cc UJM suitable for, um, "mature" beginner?

[Frankienuckles]

I think fixing older japanese bikes can be ok as long as you know what the particular model that you are bringing back to life can be bought for in good shape. Try not to spend more than the bike is worth in total(fixxer upper + parts + labor), parts can add up real fast and then you have spent $1500 for a bike you could have gotten for a grand in ok shape by shopping around.

[Busy Little Whiner]

It's not so much the amount of HP as much as the dedication to the
rigors of training...

If you have seconds thoughts about hopping into an airplane and flying
off then no one should be able to talk you onto a motorcycle without
proper training...

Now do you want to begin flying jets or would prefer a nice docile
trainer???