Recovered the seat on the 1985 Honda BIG RED 250ES. It was in sad shape and needed some foam patching too. I could not find a complete replacement seat foam so I had to patch it up. See pics and captions below for details on the job.
Seat in rough shape.
I was pleasantly surprised to find the original tool kit still in tact.
Ok removed the seat cover by removing the staples in the seat pan. A screwdriver works good for this job.
Next a quick test fit of the new seat cover before I get too far. I bought this one on e-bay for $20.00.
Next I used some old high density seat foam, cut it with a knife and glued it to the seat with some spray adhesive. The closer you fill in the voids the better the seat will look when finished.
Using heat gun to help stretch the new cover.
Using pneumatic stapler to fasten seat cover to seat pan.
I started at the front then the back and then the sides. Make sure to stretch it good and use the seams in the cover as a guide.
Note this was an early job - I have improved with better methods and materials.