When I bought my X I wanted to lower the bike a bit but did not want to buy a shorter seat, or lower the rear link. I decided that cutting down the seat would save me some cash, widen the seat a little, and allow me to keep the stock cover. I just ran across the photos I took during the process so I figured I would post what I did in case someone else wants to give it a try (forgive me if similar is posted elsewhere)...
Things you need:
Long, sharp knife, or electric carving knife
Pliers
Staple gun
Shoe Goop (other other flexible adhesive)
Stiff, thin wire
Marker
Electrical tape
Sander or sanding block, with 120-180 grit paper
60 grit paper
Spray paint (any color, just not the same as the seat foam)
Scissors
Ruler
Hammer and punch
Remove the seat, and then take the staples out to remove the cover.
Poke a small, rigid wire into the seat foam to find the top of the seat pan. Try to go straight in. Make new holes by adjusting up and down the foam until you find the top, don’t wiggle the wire. Do this every 4 inches marking the holes that indicate the top of the pan.
Using the ruler and a steady hand, connect the dots so you know where the seat pan is. Cutting to close to the pan will result in a very hard seat, and going too far, well, now you’re really sitting on plastic instead of just feeling like it.
If you have a logo on the seat and do not want it to wrap below, as with the Honda logo, measure out where the logo is normally and mark –one side only- with where it is normally.
Mark the amount of foam you want to trim with tape. Electrical tape is flexible enough to make the curves, yet won’t stick enough to ruin the foam. I spent a little time looking at how the cover would fit as I trimmed things. Because of this, I highly recommend you do not cut the front 3, or rear 1-2 inches of the seat foam for 2 reasons, 1) the seams on seat cover, or sewn curves, will still fit as intended 2) messing with the edges, especially the front, will make taking the slack out of the cover very hard.
Trace the cut side of the tape, and then remove it. Make sure you like what you see, and then adjust if needed. Using the logo marking as a reference, mark on the opposite side where the logo will land if you cut using the lines you just drew. Make changes if needed.
Using a sharp knife or an electric carving knife (which is what I used), make thin cuts in the foam. Go slow to avoid tearing the foam. Work your way down to the cut line, stopping just before the line. Pay attention to what the foam is doing. Some parts of the foam will already have splits that require you to go really slow (especially if you have used the seat), others will just split regardless of how careful you are. Just keep the damage to a minimum and fix it in one of the other steps.
Mist the top of the foam with some paint and let dry for a little bit (again, just mist it). Once dry enough, use a power sander or a sanding block and elbow grease. Hit the foam with 120-180 grit and sand down the high spots, using the paint as a guide. By hand will take some time. Don't rush this.
Test fit the seat, and make and adjustments if needed.
If you have tears or voids, GENTLY score them with some 60 grit paper and then put a small amount of shoe goop in them. Grab some of the foam dust from the sanding and put it on the glue. Repeat this process a couple of times while gently working the glue/dust into the crack. Don’t worry about perfection. All you want to do is get enough of a mix in to keep the foam from having a soft spot later. Biggest thing is to not make a tear worse. Top with a little more glue and dust if needed. Only the big cracks/voids need attention. After the fill dries, hit them with some sand paper if needed. Also hand sand the edges of the foam to give it a nice soft roll.
After the fill dries, refit the cover. Starting at the front, then rear, staple the cover. You staples should be about 1/2 inch apart. Some spots are hard to get the gun to rest completely against the pan so the staples will be high. Using a punch and hammer, get the staples to go in fully, or at least lay flat.
Once the cover is in place, trim off the excess. Bolt the seat on and your good to go.
This is the same seat 2 seasons later - still looks great!