One of the things I've learned is recognizing the type of grass you have makes a big difference in mulching efforts. A Kentucky Bluegrass as an example is much more dense than a Fescue or a Ryegrass . . For the same height. Mulching vitally depends on speed of cutting blades and spacing of grass blades and lack of water. So mulching a less dense grass doesn't hold moisture as much or slow the cutting blades down as much. Moisture and density slow blades.
What I'd look for or do is:
1. Look under your deck for buildup on the deck. If you have it . . take the deck off and clean the buildup off. Soak the buildup if needed. You want to see yellow paint everywhere.
2. Just like a car or truck . . Washing and waxing keeps dust and dirt from collecting . . so after cleaning the bottom of your deck . . Spray it with a Teflon type product like No Mow spray or other brands (available at TSC, Fleet Farm, etc. etc.) . The key just like waxing is 2 light coats not 1 heavy coat and let it dry well. This should last for most of the full season depending how clean you got it to start with. Incidentally . . spray your mulching plug too and the area around the blade spindles. Also while deck is off is a great chance to grease the zerks under the deck. Every way to reduce resistance and keep blade speed up makes for better mulching.
3. If you have a dense grass . . then dry grass needs to be DRY grass to get a best result. And if your goal is a grass cut at 2.5 inches . . and your grass is 5 inches when you start . . either slow your forward speed or double cut . . because proper mulching takes power. If the grass is higher than 5 inches . . you'll need to double cut at different heights.
4. I had one lawn that had a lot of weeds in it. Weeds hold more moisture than grass.
5. I have an I1050 and it does a good job mulching . . however make your judgement after 24 hours . . because mulching requires the "mulch" to drop into the dirt. Normal discharge cutting wipes the grass away so it looks clean . . mulching depends on absorbing it away . . So it won't immediately look as clean but 24 or so hours later it should be much better.
Of course the above assumes your throttle is set to full . . Your blades are mulching blades . . and sharp . . and your engine is running smoothly and you are using "water free" gas . . either non ethanol or using a gas treatment and plugs and carb are clean.
Hope this helps.
