Lessening power to blade, less cut grass lift

Either not enough engine speed, grass is too wet or to thick or you need a hi lift blade to cause more wind in deck. This is if deck has not been damaged s.a. inner guides bent or removed.

Mulch plugs are typically a cover that is affixed to the discharge chute of a mower deck. As blades spin, they cut grass, and lift them up into the swirling air above the cut grass and below the mower deck. The clippings are suspended until they are blown out of the chute.

Mulching, is the process where grass clippings aren't simply discharged out of the chute after cutting; rather they are kept under the mower deck and spin around suspended in the blades resulting in repeatedly being cut. Instead of long clippings exiting the chute, much smaller clipping result from multiple cuttings and settle back on to the lawn under the deck. The smaller clipping allows them to decompose much quicker and return nutrients to the lawn.

Long clippings take longer to decompose and can turn into thatch on top of soil between blades of grass - effectively smothering the lawn. Long clippings can sit on top of cut grass and choke off sunlight, etc. and cause dead spots. Thatch can occur with mulching too - but takes longer to accumulate.

I nearly always mulch

either the engine speed is to low or the belt is slipping how old is the belt is there a oil leak that got the belt wet with oil?

is the blade loose?is the pulley key way sheared as well as the key on the flywheel

Yes, it sounds like you need to adjust the blade brake clutch (BBC). I have a PDF service manual that explains it. If you post your email address I can upload it to you. Here's an excerpt from the manual:

BBC
BBC Adjusting the Blade Brake
1. Stop the engine. Pull the wire off the spark plug.
2. Remove the two screws securing the screen
panel to the top of the mower housing as shown
in Figure 22. Remove the panel. (The panel they're
referring to is the red screen between the motor
and handle.)
3. Move the control bar down and lift up against the
handle. With the control bar against the handle,
measure the spring length (L) at the front of the
spring as shown in Figure 26.
4. If the spring dimension is greater than 32 mm
(1-1/4") an adjustment is needed.
5. To adjust, loosen the bottom jam nut on the blade
brake cable as shown in Figure 27. Adjust the top
jam nut until spring dimension is as near as
possible to nut; not less than 25 mm (1") See
note below.
NOTE: Adjusting the top jam nut too high can
cause the cable end to crush the plastic fitting
when the control bar is moved up against the
handle. If the spring cannot be adjusted to less
than 32 mm (1-1/4") before the cable end
contacts the plastic fitting, the clutch belt is worn
out and should be replaced. After replacing the
belt, adjust the cable per the above procedure.
NOTE: 1990 and newer models are equipped
with finger tip adjusters that do not require tools.
Use the same adjustment criteria on these
cables.

The belt should last longer than 6 months. The mechanics should not simply replace the belt without investigating to find the cause. Have them take the deck off and look at it closely, as well as studying the failed belt to see if it's been worn down as a result of constant rubbing, or if it simply snapped as a result of something seizing up suddenly.
Possible causes: a blade spindle could be binding, or an idler pulley could be binding or misaligned. With the belt off, check that these all spin freely and don't have excessive play. The belt could be also the wrong size or not the heavy-duty kind needed. Finally, if the blades were very dull that could also shorten belt life, but you would have noticed that by the poor grass cutting results - brown, frayed ends on the grass.
Good luck! Please rate my answer if helpful, thank.

If the grass is very tall (more than 10") you will have to slow down to less than 1 mph, if you have a mulch kit on this unit, remove it to get the grass out as quickly as possible. Also, sharp blades & a level deck are important.

The high grass causes more drag than shorter grass. This means more friction. The tilting lessens the drag, so less friction, the speed increases. It ma need a sharpening but it sounds as though it is running correctly. As you say, it is older so you can't expect new performance. Good luck...Lee

Hello monica_skinn:

If the Underside of the Deck is Clean and the Blades are Tightened Properly, then the Problem is Caused by the Blade Lifts being Worn or the Blades are Not a High Lift (Bagger Blade) Blades.
A Bagger Blade has a Very High Lift Ear on the Backside of the Blade Across from the Cutting Edge. This Extra Lift is What Gives the Extra Lift and Throw (by increasing air Flow under the Mower) the Grass gets to be Bagged.
Please, Do Not Hesitate, If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance.
Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Be Happy. Thanks.

Good Luck

Respectfully

jbridger (John)

It sounds to me like a very loose belt or very worn out belt and also an adjustment problem.