I wouldn't recommend it. 3200 is pretty much the max for blade tip speed. Try a new blade and make sure the mulch fan is in good condition and not coated in residue. The deck should be clean too. This mower is known for excellent mulching. You may have to cut more often this time of year with all the rain we've had.

I guess the 3200 is a safety mandate, because it seems the faster the blade spins the more action you get.

When I was a kid I started mowing lawns at about twelve years old. I teamed up with a neighborhood buddy, we actually had quite a biz, doing upwards of a dozen or so lawns a week at 5.00 dollars per cut. When I started my dad let me use the family mower, but told me as soon as I was profitable enough to buy my own mower for my biz.

I soon was able to buy a new mower, I chose a craftsman 20 incher push with aluminun deck and adjustable wheels. It had a huge white aluminun shroud covering the engine and and a novel new starting system, a huge spring. You would unfold a crank where the starter rope normally is and wind up tight a huge spring. When folding the handle back over a pin would engage a release mechanizm and spin the engine, hopefully starting it. As I recall, the 3 hp tecumseh ran exceptionally smooth, probably because the large metal shroud dampened out vibration. With boyish ignorance and enthusiasm I painted little signs on the shroud, '100+ octane only' and 'veedol special only'. I ran sunoco 103 octane gas thinking that would really soup up the power and even fitted a 'velocity stack', emulating the stacks on my bothers souped up flathead tripower ford.

Anyway, to the point of my story, I guess. In order to negotiate and put to death heavy clumps of grass with my 3 hp tecumseh I ran a 18 ga. bell wire from the governow rod to the handle. As I would approach a heavy stand of grass I would pull back on the bell wire and that old indian would wail like a banshee, spewing clippings out of that old crapsman 10 feet (it seemed like it ,anyway). It never stalled out and the indian never blew. My buddy thought I was crazy, but saw my results and thought he would give it a try. Only problem was, he had a briggs. His motor lasted a couple of days and then one sunny afternoon while mowing Mrs. Fleets' 30 ft berm there was a loud mecahical BANG! and a piece of rod sailed past my head at the bottom of the hill!!

My old mower was still running when I went off to college, but considering I ran it for years without an aircleaner it must have been a disaster inside.

I'm laughing myself silly, sitting here thinking about those days long ago when the world in my mind was at peace, and the only thing I had to worry about was a hot summer day and Mrs. Fleets' hill.

'I guess the 3200 is a safety mandate'

That's right. Before this mandate, the standard RPM was 3600. I forgot to mention trying a slower ground speed to increase mulching. Great story about the old Tecumseh. Reminds me of stupid stuff I did.

Increasing rpm can well improve air flow in that old mower. All it had to do was cut and throw. Mulchers though are modern mowers. The blades, deck design and any added air flow devices used to circulate the grass to allow for multiple cutting are designed to work most efficiently at 3200 rpm.

Going faster will alter the intended air flow in mulching mode. If performance isn't what is expected it is more due to other factors messing up up air flow. Cutting to much at one time, mowing wet, dull blade etc,