Husqvarna Mower Dies When Blades Engaged: A Definitive Guide


Husqvarna is one of the most popular outdoor power product manufacturers in the world. Its riding lawn mowers are one of the most popular in the USA. Plus, with a selection of budget-to-premium models, Husqvarna is popular with everyone. However, many users also experience problems, especially with older mowers. Here, one of the most common issues is that the mower dies when the blades are engaged. If you’re having this problem, troubleshooting the mower is relatively easy. 

If your Husqvarna mower dies with engaged blades, you could have one of several issues. Here, the most likely problems are belts, pulleys, safety cutoff switches, or the battery. Diagnosing the problem requires some inspection of your machine, but chances are you can DIY with a minimum of time investment. 

Note: When troubleshooting, mechanical issues are more likely than battery ones. Therefore, it’s always a good idea to look at mechanical issues first. 

9 Factors Why Your Husqvarna Mower Dies When You Engage the Blades

If your Husqvarna mower dies when you engage the blades, it’s likely one of these 9 predictable reasons. You can troubleshoot using the following guide. 

1. Seat Safety Switch 

Most mowers have three safety switches to prevent blades from running when someone isn’t in the mower. These include the switch that activates the blades, the one on the brake pedal, and a third switch under the seat. Unfortunately, this switch can come loose or may be faulty. Here, the most common cause is from vibration. 

Fixing the Seat Switch 

  1. Flip the seat up or pull the seat off depending on your model 
  2. Unplug the seat switch
  3. Clean the connection
  4. Check for any loose or naked wire ends 
  5. Plug it back in firmly
  6. Test if it works 

It can be difficult to test if a switch has gone bad without a multimeter. However, you can use a multimeter to check if the switch is engaging when depressed. 

It’s also a good idea to look at the connections to the other switches. If your primary and brake switches aren’t working properly, your mower will always die when you engage the blades. If your switch is dead, it’s usually a simple matter to look up the part number and replace it. 

Alternatively, some people prefer to move the switch to the back of the seat. This ensures that you put more pressure on the switch when sitting. However, it won’t resolve issues with a faulty switch. 

2. Frozen Pulley 

The pulley is driven by the drive belt. Here, it turns the spindles that power the blades. If it doesn’t spin freely, your lawn mower might die when you engage the blades. 

To check: 

  • Follow safety precautions and turn your lawn mower off. Allow it to sit and cool for several minutes. Then, access the motor. 
  • To check the pulley, first remove the drive belt. 
  • Lift the lever to engage the blades. 
  • You should be able to spin the spindles by hand. Spin the idler pulleys on the mower deck. 
  • If the pulleys don’t spin or growl when spun, it’s a sign to replace them. 

First, you always want to check for debris or buildup that could be blocking the pulley. For example, grass, sticks, and mud can easily accumulate in the motor. These can cause large issues. However, if there is wear or abrasion on your pulley, it’s always a good idea to replace it. 

How to Replace the Pulley 

  • Remove the drive belts
  • Pull out all 6 pins from the front and back of the deck using needle nose pliers 
  • Disengage the safety bar 
  • Detach the blade deck and slide it out 
  • Put the tractor on ramps or use a jack to access underneath the tractor
  • Check the pulleys 
  • Use a 16th inch socket wrench to detach the pulley. It may be helpful to use a second wrench to hold the bolt on top in place. 
  • Remove the pulley 
  • Replace the pulley with a new one by putting the bolt back in place
  • Replace the deck 

3. Seized Deck 

Accumulating dirt and debris can build up under the deck, which can cause the blades to seize when you engage them. This will cause the motor to stall. Here, the only solution is to clean the mower. To do so, you want to remove the deck to clean it. Otherwise, you can choose to put the mower on a ramp and use a power washer to clean under and around the blades and around the pulleys. 

Good mower maintenance means regular cleaning. It’s important to inspect the deck and the blades for built-up debris if you want to keep your mower in good shape. Keeping the deck and blades clean can prevent further problems with the mower.

4. Faulty Battery Can Cut Mower Off

While mechanical problems are more likely, you might also experience battery-related problems. Here, your mower may cut off when you engage the blades if they are pulling more power than the battery can supply. In this case, you can replace the battery. 

Things You’ll Need 

  • Gloves
  • Voltmeter or multimeter

How to Check the Battery 

Use an electric voltmeter for the best results: 

  • Change the setting on the meter to DC or A 
  • Set the meter to 13
  • Clamp the leads onto the posts, paying attention to +/-
  • IF the reading is under 12, the battery is not fully charged
  • If the reading is under 12.4 you want to replace the battery 

You can always try charging your battery overnight. If it doesn’t increase the charge, replace the battery. 

5. Carburetor Issues 

The carburetor mixes air and fuel before injecting it into the engine, creating an optimal mix for combustion. If the mix is off, the fuel could have too much or not enough air to power the engine. Problems might be caused by clogs or by buildup around the intake, which means insufficient air is pulled into the carburetor. 

Regularly cleaning your carburetor is part of good mower maintenance. However, for most, once a year is more than enough. 

How to Clean the Carburetor 

  • Turn the ignition switch off and remove the key 
  • Disconnect the battery 
  • Access the motor
  • Remove the air duct
  • Remove the air filter cover. Most Husqvarna models have knobs you can simply turn 
  • Remove the air filter housing 
  • Clamp the fuel line 
  • Use a bucket or rag to catch drips and remove the fuel line from the carburetor
  • Disconnect the breather tube and air intake from the carburetor
  • Disconnect the solenoid 
  • It’s good practice to take a photo of the full setup before disconnecting throttle rods and strings or the choke rod
  • Remove the intake gasket and clean the surface
  • Remove the carburetor
  • Clean your carburetor. Here, it’s a good idea to soak the carburetor overnight in a heavy-duty cleaner intended for machine parts. A turpentine solution is also suitable. 
  • Use a bottle brush to clean out each of the gaskets. Scrub the housing down. It’s a good idea to note if there’s a lot of buildup. If not, dirt might not be your problem. 
  • When the carburetor is dry, put it back in. Be careful to reattach everything as it was. Here, you should pay special attention to the throttle rods and strings and the choke rod. Do not mix them up. If you’re still having problems, it might be a good idea to replace the carburetor. 

6. Improperly Routed Belt

An improperly routed belt can stop your motor in its tracks, as the belt is unable to thread through the machinery. Here, you might see similar issues with a worn or frayed belt. Threading issues are unlikely unless you’ve recently replaced the belt or had it replaced. However, fraying and wear issues are likely on any older belt, especially if there are other engine issues causing wear on the belt. 

Luckily, placing the belt properly is not difficult. You can easily fix this problem in a few minutes. 

How to Route the Belt

Follow safety steps to turn off the engine, allow it to cool, and remove the keys. Disconnect the battery. Make sure you engage the safety break. 

  • Lower the deck to its lowest setting 
  • Unbolt the belt guard 
  • Lift the belt over the pulley
  • Remove the 6 pins holding the deck in place 
  • Slide the deck out from under the tractor
  • Check the belt for wear and tear or fraying 
  • Cross-reference the belt routing with your manual 
  • Remove spindle covers before removing the belt
  • Re-route according to the instructions in the manual

In most cases, an improperly routed belt will not be the issue. The only time you should be concerned about belt routing is if you’ve recently replaced the belt. However, fraying and wear are problems, and you can easily inspect for them. 

7. Check the Fuel System Line 

Clogs can happen at any point between the fuel cap and the fuel injection. A clogged system prevents air or fuel from getting to your motor. That can cause it to cut when you demand more power, because the engine can’t supply it. Normally, this is a simple matter of inspecting the fuel system from start to finish. 

  • Fuel cap is clean and air holes are free of clogs
  • Fuel lines are clean, free of clogs, and not kinked, broken, or damaged
  • Filters are clean and not clogged 
  • There is no buildup around connections which might indicate a leak 

Fuel lines, fuel filters, and air filters are easy to replace and cheap. If you spot problems, it’s often a good idea to simply replace the damaged part. However, if there are clogs or dirt, it’s easy enough to clean fuel lines. 

8. Grass Being Too High 

If your grass is too high and dense, your lawn mower could have difficulty powering through it. That’s especially true if you’re trying to cut an overgrown yard which might have weeds and other dense growth. Grass height impacts the power needed to cut through the grass. If you try to cut something too difficult, the mower could lose power. 

In this case, try running your mower on an open lot to see if it’s having issues there. If not, pre-cut the grass with a different mower first. 

9. Engine Oil Level 

Engine oil is necessary for lubricating the engine and preventing it from overheating. However, if you’ve overfilled the oil container, it could be causing problems. Here, oil will spill, which will likely mean going onto the crank case. That can prevent proper fuel vapor combustion, which means your engine will stall or will lack power. Similarly, if oil gets into the exhaust or intake, it will prevent airflow and therefore combustion. Eventually, excess lub oil is always a bad thing. If your engine has motor oil or oil buildup inside, taking the time to clean it out can restore your lawn mower to working condition. 

FAQs

If you still have questions about your Husqvarna mower, this FAQ might help. 

Are Husqvarna lawn mowers any good?

Husqvarna lawn mowers are extremely popular. In addition, Husqvarna offers a 3-year warranty on all mowers. However, “good” is subjective and you may prefer a Husqvarna or another model. 

How long do Husqvarna mowers last?

Husqvarna claims that with good maintenance, its riding mowers should last about 15 years. However, the longevity of any riding mower depends on maintenance, conditions, fuel, and usage. 

What causes fuel lines to go bad? 

Fuel lines normally go bad because of old fuel, clogs, or damage to the lines. For example, if your lines are sitting open in the sun, they can become damaged. The largest cause of bad fuel lines is buildup in the line. 

Summary 

Hopefully this checklist has helped you to solve your riding mower problems and your blades are finally engaging. It’s frustrating to try to use your mower only to have it die when you engage the blades. Ideally, this guide helped you resolve it. If you’re experiencing other problems, hopefully you can check our other articles for more insight. 

Have a question you don’t see on our sight? Ask us and we’ll try to answer.

Recent Posts