Poulan Pro 22" does not mulch!

twice a season or every 40 hours

This sounds like a simple belt adjustment. Look in the area where the belt is . Look to see if there is an adjusting screw, or a movable pulley, or just something that will tighten the belt. Lift the mower and look underneath the mower deck. This may be where the adjustment may be. If you can't find the area of adjustment, then you may have to bring in to the repair guy. Either way it's cheaper than a new mower. GOOD LUCK>

I believe that engine speed will adjust travel speed. GOOD LUCK.

Your Poulan Pro mower is made by American Yard Products and the parts will interchange directly with Craftsman 22" mowers. You should be able to find a replacement at your local Sears store. All of these part #s are also 22" AYP blades:
AYP #'s
406713
192682
157101
335256
114886
141114
Rotary #15-6236
Oregon #
95-043
95-042
95-055
95-023
95-021
95-602
The different #'s should all fit. Some of them are bagging style blades (high lift) while others are designed to mulch.
Online sources will include www.searspartsdirect.com and www.amazon.com

Good Luck!

Yes

just regular unleaded,same as you put in your car.

there should be a drain plug under the mower near the shaft that the blade is connected to... good luck

remove spark plug wire from plug,tip machine on its side.look under blade for a threaded plug with a square head where bottom of motor protrudes through deck.on most models you can simply tip machine over far enough to allow oil to drain out the dipstick[filler]tube.

Verbally threaten to trade it in for a riding mower.

if its new take it back tell them you want one that doesnt leak
be sure it is not overfull of oil
if you dont want to take it back replace the crankshaft seal