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Frequently Asked Questions

Check the most frequently asked questions here, if you still need help then please contact us at


Every item that is a part of a GrassFlap unit can be purchased as an individual item, if needed. Refer to the first page of the installation guide to help you determine what part you need. Spare parts may be purchased on the Spare Parts section of our website.

The best way to identify the GrassFlap unit you need for your mower is to use our product look-up tool.  Enter your mower information and it will direct you to the correct unit.  If you do not see your mower listed, email us at and we will help you find the correct unit.


The deflector angle should travel with the flap to prevent clippings from blowing straight up as the flap begins to open. As it first begins to open, there is not enough angle to deflect the clippings down so they end up blowing around, up and down. Without the angle, grass clippings will go straight up and onto the mower operator. Mounting the angle to the deck only provides a good seal when the flap is fully closed.

Installation videos may be found on our YouTube page. If you don’t see your exact mower, chances are a different installation video would have similar steps you can reference. If you are having any issues with assembly or operation, please contact us at 502-594-3546 or

The deflector angle should be positioned between the plastic blocker plate and the hinge plate with the red tape against the hinge plate. The tape will not stick to the plastic blocker plate.


Yes, the flap can be held in a partial-open position using the foot pedal. Simply hold the pedal in the desired position. One of the nice features of the GrassFlap is its pedal operation, allowing the flap to open and close without the need to push on a separate pedal. It’s easy to push and release the pedal in one smooth motion to open the flap, and the same for flipping it back to the closed position. Locking the flap somewhere between fully open and fully closed requires a second motion to lock and release it.

Short answer, no. The GrassFlap is designed to be a temporary discharge chute blocker, not a mulch plate. 

This leads to a conversation about mulching versus temporarily blocking the discharge opening. 

Mulching involves cutting the clippings multiple times until they are small enough to drop into the lawn and not clump. Mulching requires baffles to hold the clippings around the blades and special blades to recirculate the clippings. The blades lift at the tip and push the clippings down in the center. Successful mulching is limited by how thick and tall the grass is.

Compare this to traditional side discharge mowers with high lift blades. The blades are designed to move a lot of air for lifting the uncut grass, while a deck includes baffles designed to move air smoothly toward the discharge opening where it is expelled. This air flow is what carries away the clippings. If you want proof of how well it works, just stop next to some tall grass or debris on the trim side of the deck, and watch it get sucked under the deck. 

So, what happens when you close the discharge opening? The air continues to be pulled in but must find a new way to escape. The clippings continue to travel toward the discharge opening where they pile up. Simply closing the discharge does not force the clippings to stay around the blades. It does not matter what is used to block off the opening, the grass will collect and the air will find a way out. 

Often these clippings will escape with the air. There are certain conditions that exaggerate the problem of clippings escaping with the air. When the grass is dry it tends to escape more, as well as when the lawn is thin. Thick lawns tend to filter the clippings. 

The GrassFlap is like any new tool, you have to learn how to use it. 

Fully close the flap only for short periods, or when you are discharging into uncut grass that you will mow later. You can partially close the flap anytime to control how far the clippings fly and keep them from collecting behind the flap. The advantage of the GrassFlap foot pedal is the ability it provides to change how far open or closed it is while the mower is moving.

The flap can be opened and closed with the same push and release motion. The proper  operation is to push the pedal down until the flap approaches the half open position, then the pedal should be released, allowing it to rise as the flap passes the halfway point. If you watch the video and continue to have issues, please contact GrassFlap at 502-594-3546 or

GrassFlap How to: Operating the Pedal - YouTube

The flap is designed to open halfway with the pedal in the fully-down position. Pushing harder will not cause the flap to move. The proper  operation is to push the pedal down until the flap approaches the half open position, then the pedal should be released, allowing it to rise as the flap passes the halfway point.

First a little background info. Mowing decks are designed to move air from under the deck toward the discharge opening. The air flow lifts the grass before cutting and then once cut, moves the clippings out from under the deck to make room for more incoming grass. All side-discharge decks create a tunnel in the front right corner for the grass to be transported. This happens by setting the right blade back a small amount. This tunnel carries the bulk of the clippings to the discharge opening. There also is a baffle at the rear of the discharge to help push out any clippings above the blade that didn’t exit at the front of the discharge opening. This system is designed to expel as many clippings as possible on the first pass. 

When the discharge opening is blocked, the air must escape somewhere, or cut quality will suffer. Blocking the opening is a trade-off between blowing grass into unwanted areas and quality of cut. True mulching systems (not temporary chute blockers) are designed with extra baffles that encircle each blade to hold the clippings at the blade until they are chopped finely enough to fall back into the grass. 

Without the mulching baffles, air escapes from under the deck wherever possible if the discharge is blocked. The collection point is typically the front right corner, so naturally that is where most air and clippings will escape. Additionally, when you first begin to open the flap, clippings will hit the plate and go all directions—up, down, and all around. Once the flap is opened to a sufficient angle, the clippings will be deflected down and out. The quantity of clippings blowing up can be redirected with a deflector angle to prevent them from blowing on to the operator. In most cases, deflected clippings end up on the mower deck, so blowing off the deck on a daily basis is beneficial. 

All that said, there are a few things you can do to improve the performance of temporary chute blockers.

1.  Only close fully when needed and don’t leave closed for long periods.

2.  Close partially to allow clippings to be deflected down slightly, allowing clippings to escape and not pile-up behind the flap.

3.  Mow your first pass on the second row in, discharge closed and pointed out. Then, open discharge and mow the first and third rows with discharge pointed in.

4.  Open flap while turning to distribute clippings that have collected behind the flap.

Given enough pressure, it will push open. It is held closed with the spring; the same spring holds the flap in the open  position. By the time the flap is pushed open, there typically is enough grass caught behind that you are likely no longer making a good cut.

Returns and Warranty Claims

GrassFlap will only accept returns with prior approval.  If you wish to return a product, please send an email to explaining the reason for the return request.  You will receive a confirmation email with return policy and return shipping label.  A $35.00 restocking fee will apply, see return policy for additional fees that may apply.

DO NOT REMOVE cable conduit from the mower.


1.      REVIEW THE CABLE INSTALLATION USING THE CABLE INSTALLATION CHECKLIST, look at each item on the checklist from the original installation and confirm the cable is still installed properly. If you find the set-up has changed, then most likely this is the cause of the failure.


2.      TAKE PICTURES of cable conduit as it is routed on the mower with broken cable wire alongside the conduit, just as if the wire were run in the conduit. Picture must show both the cable and the conduit in the same image. Pictures are required for a warranty claim.

3.      CIRCLE BROKEN END OF WIRE in picture from step 2 (edit photo on your smartphone)


a.    Pictures of broken cable, (from step 2 above)

b.     Picture of Completed "Cable Installation Checklist", (from step 1 above)

c.      Approximate purchase date of current cable.

d.      Location where cable was purchased and name of purchaser.

e.      Subject line "BROKEN CABLE"

If you need a replacement cable right away, we suggest you purchase one online, so it will be headed your way while we review the above information.

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