Mower Dies When Engaging Blades

Several reasons could cause your lawn mower to die as soon as the blades are engaged. These include a faulty safety switch, dirty carburetor, weak or failing engine, or improper electronics.

This is a common problem with old lawn mowers, but it can also happen with brand-new mowers. An interesting study published by The Atlantic, found that one-third of American homeowners prefer not to cut their own lawns. That leaves two-thirds of US homeowners doing it themselves. This results in a massive online community asking questions like, “Why does my mower shut down when the blades engage?”

The team at Mowrator USA has compiled this guide to help you understand why your mower dies when engaging blades and what you can do about it. We’ve got a list of the 8 most common reasons and their respective solutions, so let’s get started!

Key Takeaways

• Mechanical issues like faulty wiring, a dirty air filter, or a clogged carburetor can cause your mower to die when the blades are engaged.
• Keeping your mower deck clean will prevent the blades from getting jammed.
• Most lawn mowers have a safety switch that can get triggered when the mower detects obstructions like dirt.
• Riding mowers will not engage the blades when the mower is in reverse mode, unless you override the reverse safety switch.

8 Reasons Why Your Mower Dies When Blades Engage

Here’s a summary of why your mower shuts off when the blades are engaged, as well as some solutions. Scroll down for a more detailed description and solution for each reason.

Malfunctioning Safety Switch

Your safety switch is there to switch off the mower when it senses danger. However, sometimes this switch can malfunction and cause your mower to turn off when it’s not supposed to.

Solution: If your mower is still under warranty, take it back and get the supplier to replace the mower or the safety switch. If your mower’s warranty has expired, you’ll need to buy a new safety switch and replace the old one.

Worn or Loose Belt

The belt in your mower transfers power to the blades and makes them spin. When this belt is not fastened properly, it will slip and fail to transfer power correctly.

Solution: Replace the belt or make sure the old one is aligned properly. If it’s worn, you’ll need to purchase a new one and replace it.

Blocked or Contaminated Carburetor

After some use, your gas mower’s carburetor can accumulate dirt and grass clippings. This will restrict the flow of fuel and kill the motor when the blades are about to engage.

Solution: You’ll have to check the carburetor and clean it out. You may also need to drain the fuel and refill your mower with fresh fuel.

Underperforming or Faulty Engine

Older mowers may manifest wear and tear to the engine. If your mower is fairly new, this shouldn’t happen, and you should claim your warranty. An old mower may need the air filter replaced, or the spark plugs changed.

Solution: Replace the air filter and install new spark plugs. If the problem persists, take your mower to a professional mechanic to check the engine.

Clogged or Jammed Mower Deck

Debris and grass clippings may build up and get stuck to your mower deck. When this happens, it jams the blades and triggers the safety switch to protect the engine against burnout.

Solution: Clean out your mower deck and lift the mower height slightly to get the blades moving again.

Riding Mower in Reverse Mode

Your riding mower may also die when the blades are being engaged. This is sometimes due to the mower being in reverse mode. Your mower will switch off the blade rotation when in reverse, so make sure it’s not in reverse gear.

Solution: Switch gears to normal or use the reverse override setting to engage the blades while the mower is in reverse.

Debris or Blockage Beneath Cutting Deck

The lower parts of your mower’s deck may also accumulate wet, caked grass clippings or debris. This will restrict the blades from spinning and activate the safety switch.

Solution: Clean out the bottom of the mower deck. Make sure you switch off the mower before doing this to protect your hands. Keep testing the mower until the blades spin again.

Wiring Issue or Poor Electrical Connection

Faulty wiring can cause all kinds of problems with your mower’s engine. If any of the wires are broken, jammed, or knotted, your engine will act up when you switch the mower on.

Solution: If you’re familiar with wiring, open up the mower and check that all wires are in good condition and connected properly. If you’re not familiar with fixing wires, take your mower to a mechanic.

Mowrator supplies high-tech, self-propelled lawn mowers that are capable of handling the toughest of gardens. Find a dealer and speak to them about our mower models and pricing to get the best mower for your lawn maintenance.

Mower Dies When Engaging Blades FAQs

Can a faulty seat switch cause the engine to stall when engaging blades?

Yes, a faulty seat switch can cause the engine to stall when you engage the mower blades. That’s because some riding mowers have detection technology that switches off the mower if there’s no one sitting in the seat of the riding mower.

Can a bad battery cause the engine to die when engaging blades?

Yes, a bad or flat battery in battery-operated mowers will struggle to engage the blades due to insufficient power. You can charge the battery or replace it with a new one so that enough power can be transferred to the pulley and spin the blades properly.

Does the position of the mower affect blade engagement?

Yes, sometimes the position of your mower can affect blade engagement. When your mower is on a slope, the blades may be hitting against the ground instead of just the grass. This will trigger the mower’s safety switch and cut the engine when you try to engage the blades.

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