Best Lawn Mower Engines 2020 – Buying Guide and Review

Lawn mowers are an integral part of your household. These are powerful machines that will keep your lawn looking great all year round and incredibly easy to operate. It’s only natural that at some point you’ll have to replace the engine, but it can be challenging finding the best lawn mower engine if you’re doing it for the first time.

Having a beautiful, nice green lawn is what most homeowners dream of having, and since your lawn is often the largest part of your garden, you need to use a quality lawnmower that will suit your grass and the size of your garden. However, there are many different mower models in the market and without the right information, you can easily choose the wrong mower engine. So before you buy a lawn mower engine, there are several things you need to consider.

List of the best Lawn More Engine

Briggs & Stratton 33S877-0019-G1 single-cylinder engine

This is a single cylinder that can provide 540cc of dependable power for your machine needs. It also has a 19 horsepower rating that is very effective in terms of efficacy and a pulse fuel pump with full-pressure lubrication with oil. The overhead valve helps to keep the mower’s engine cool when in operation while its unique design ensures it lasts longer. This engine also comes with a 9 amp charging system and a Dura-Bore cast iron cylinder sleeve that ensures the longevity of your engine so you don’t have to worry about replacing your engine for a long time.

The electric start function makes it easier to start the mower’s engine while the magnetron electric ignition of this engine is maintenance-free so you don’t have to keep checking to see if it’s working. This engine comes with a pre-installed muffler which keeps the noise of the engine to a minimum when you’re using it to avoid being a nuisance to your neighbors. This engine comes with a manufacturer’s limited warranty of 2 years for consumer use and a 1-year warranty for commercial use.


  • Very easy to install and straight forward
  • The engine starts on the first try
  • It runs very well
  • Doesn’t produce a lot of noise


  • Doesn’t come with supporting documents


A powerful engine that is very easy to install and comes with engine mufflers so it doesn’t produce a lot of noise.

Briggs & Stratton 49T877-0004-G1

This is the perfect engine for your mower that you can use in your commercial jobs. It’s a versatile and durable utility engine that will perform effectively no matter how tough the job is. This is a great commercial-grade engine that comes with a patented 5-step debris management system that will help protect your engine from heavy debris which will help in extending its durability. It also has cyclonic air filters that are more efficient when it comes to protecting your engine from debris. If you’re going to use your mower to perform tough jobs, the overhead valve design of this engine and its cast-iron sleeves will prevent this engine from overheating and ensures that the cooling system is running smoothly.

To ensure the strength and durability of this engine, it’s designed with a high-quality cylinder block structure that is strong and sturdy. It has a 16 amp alternator and a regulator, a twin-cylinder, and a heavy flywheel as its charging system. The 12V heavy-duty starter operates the starting system while the spin-on oil filter that works on full pressure controls the engine’s lubrication components.


  • Easy to install
  • The engine is strong and runs smoothly
  • It can make a nice replacement
  • Comes with an engine manual that’s straight forward


  • Doesn’t come with a muffler


A versatile and durable engine with fantastic horsepower, a great air filtration system, and a cooling system that will keep the engine running for longer.

Briggs & Stratton 25 HP commercial turf engine

This is an engine that is specially designed for a zero-turn mower that can handle high debris jobs and endure extended use in tough conditions. It’s a 25 horsepower engine that is both high-quality and high-powered and comes with a vertical shaft. This engine has a well-designed 5-stage cyclonic air filtration system that will effectively protect your engine from heavy debris. This is an excellent engine for mowers or tractors that carry out high-debris applications.

It’s also an excellent z-turn replacement engine for riding mowers and the best parts are the way this engine fits and is very easy to install. It bolts right in and you can easily plug in the entire wire harness without having to make any modifications. This makes it a great engine if you like doing your own engine replacements.


  • A powerful engine for cutting grass
  • It runs smoothly
  • Very good air filtration system and oil cooler
  • A strong and solid engine


  • Comes without threads in the block for the mounting bolts


A powerful and solid engine that’s easy to start and comes with a very effective air filtration system that keeps particles out of the engine.

Briggs & Stratton vertical 17.5 HP engine

If you don’t want to spend much on an engine, this engine is highly affordable. It’s a 500cc single cylinder engine with enough power for your needs. It also has a 17.5 horsepower rating and is designed for riding mowers that have a manual deck engagement. To ensure the durability and longer lifespan of this engine, it’s designed with a cast iron cylinder and a 3 amp alternator for charging the battery, but it doesn’t power an electric clutch. This vertical shaft engine uses a dual clean air filtration system that will ensure your engine is free of heavy debris and a maintenance-free magnetron electric ignition.

It has an impressive 2-year consumer use warranty and a 1-year commercial use warranty from the manufacturer. However, there are a few things that are missing in this engine that you’ll have to buy but comes with an oil filter. It doesn’t come with a fuel pump and you’ll need to get a gravity-feed fuel supply. You’ll also need to look into getting a muffler.


  • A great engine at a great price
  • Plenty of power for a zero turn mower
  • Very easy to install
  • Runs smoothly


  • Doesn’t come with a muffler
  • It’s missing a fuel pump


An affordable engine with enough power for a zero-turn mower. It has an excellent air filtration system and the manual deck engagement will work great for riding mowers.

Briggs & Stratton 31R907-0007-G1

This is a high-quality engine that you’ll get at a reasonable price and will run consistently without giving you problems. It’s a single cylinder engine with a 500cc of power and a 17.5 horsepower rating. This engine uses an electric starter that makes it easy to use with your small lawn mower while the magnetron electric ignition is maintenance-free which is a great bonus. It also comes with a dual clean air filtration system to keep the air in your engine debris-free at all times while the cast iron cylinder sleeve helps to extend the life of your engine.

The float carburetor ensures that your engine will consistently and easily start every time. The linear balancing system makes sure your engine has a smooth performance no matter how tough the job gets.  You can mow your lawn without disturbing your neighbor’s thanks to the pre-installed muffler that comes with the engine. It also has a 9 amp charging system.


  • Works as a great replacement engine
  • Runs smoothly
  • Easy to install
  • Has great horsepower


  • Doesn’t come with a fuel pump


A single cylinder engine with enough horsepower to get the job done in no time. It has a linear balancing system that ensures the engine has a smooth performance.

Kohler KT715-3040 7000 series 20 HP vertical engine

This is a high-powered engine that will work great as a replacement for residential zero turns and riding mowers. It has a 725cc engine and an amazing high power rating at 20 horsepower. It uses the Smart-choke technology which allows your engine to start at any throttle position which saves you the need to always choke your engine every time you want to start it. If you live in an area where temperatures can get to below freezing and you worry if the engine will start, you don’t have to worry because this engine will start in any weather condition even in below freezing temperatures.

The clean and consistent cut technology will help to maintain your engine speed even when mowing in tough conditions. The engine uses a PRO performance filtration system that helps to enhance the filtration of the oil, air, and fuel in the engine while the pressure lubrication ensures that all the engine components are kept well lubricated and this helps to extend the life of your engine.


  • A great replacement for a single cylinder engine
  • Has amazing power
  • Very simple to install
  • Runs smoothly


  • Doesn’t have threaded mounting bolt holes


A high-performing engine that you can use as the perfect replacement for your zero-turn engine with a great air filtration system and you don’t have to choke it every time you start.

Factors to consider when buying the best lawn mower engine

  • Engine horsepower

The engine horsepower is the measurement used to describe the engine’s power output. This power output is usually used by various components of the mower like cutting blades and the drive transmission. Most lawn mower engines are available between 140cc-90cc. So the more the cc, the more the power that can be distributed between tasks and also provide enough cutting power to easily cut any type of grass. If you’re planning on cutting extra-long grass, you’ll need a lawn mower with a more powerful engine. But if you’re just trimming a well-maintained lawn, a mower with low power will do just fine.

  • Reliability

Whether you want a lawn mower to use frequently, or sparingly, it should have a very reliable engine. Well-known brands in the industry assure their mowers to have very reliable engines, so the higher the quality of the engine, the longer it will last. Avoid going for an engine that is cheap and unbranded.

  • Fuel capacity

How much gas the mower can hold in its tank, will mainly depend on the size of the mower. Ensure that the mower you decide to purchase has the adequate fuel capacity to be able to tackle the job at hand because the last thing you want is stopping in the middle of mowing to refuel. Mowers with a small fuel capacity are ideal for handling medium-sized lawns, while the ones with a larger fuel tank are perfect for larger gardens.

  • Maintenance

How long a lawn mower’s engine will last will largely depend on how well you maintain it. This means that you have to change its oil frequently, check its air filters for replacement, and clean out debris every time after using it. You also need to ensure the oil you use is quality oil for a mower.

  • Cutting width

The cutting width of a mower translates to how wide the cutting blades can cut grass in one pass. Smaller mowers have a cutting width of about 30 inches, while the larger mowers can cut up to 50 inches or more. However, this will all depend on the size of your yard. If you have a small property or it has many obstacles like trees and hard to reach corners, you’ll need a mower with a smaller cutting width so that it can be able to easily maneuver around. But for a bigger property with a more open layout, a larger mower can do the job easily and in less time.

Your yard’s terrain

If you have a flat yard, a typical walk-behind mower will get the job done easily, but if your yard is hilly or sloppy, you’ll want to use a self-propelled walk-behind mower will do a better job because it will pull itself up the slopes. A gas-powered engine mower has more power than an electric mower. To mow large lawns with slopes, a rear engine riding mower is the best option. However, avoid using a zero-turn mower on a sloppy lawn because although it has great mobility, it has small wheels that will slip on sloppy and hilly areas.

  • Transmission

The transmission transfers power from your mower’s engine to its wheels and this propels the mower forward or in reverse. There are 3 types of transmissions that include manual, automatic, and hydrostatic. A manual transmission has different transmission speeds that you can select from. You will find it in older models where you use a clutch to change between speeds and even to stop. The automatic transmission uses a gas pedal which allows you to control the speed and this makes it easier to control your mower even when you need to slow down so you can move around obstacles. A hydrostatic transmission is the same as the automatic one with the difference being it uses liquid instead of belts to get the power from the mower engine to its wheels. This fluid system gives you a much smoother ride and requires very little maintenance.

How to maintain a lawn mower’s engine

You must maintain your outdoor power equipment regularly if you want to serve you for a long time. During winter a mower’s engine is grounded, so you must prep it before you start using it in the spring. Here are some of the basic things you can do to prepare the engine so that it doesn’t have any problems when you’re cutting grass.

  • Air filter replacement

The air in a lawn mower’s engine is mostly filled with dirt which goes to settle in the air filter of the engine. If it sits there for a long time, it can find its way into the engine and this can cause serious damage to the engine. That’s why it’s best to get the air filter replaced every 3-4 months or after 25 hours of using the mower. And for you to find the right air filter for your mower, you should check the operator’s manual of the product.

  • Oil change

It’s recommended that you should get your mower’s oil changed at least twice a year because oil tends to gather dust and debris that can cause harm to your engine on the inside. Also, if you use your engine regularly, the heat tends to break down the oil so regular oil changing can help prevent such kind of damage to your engine. You can use an oil removal pump that you can get at engine dealers to change the oil and always the instructions in your engine operator manual when adding fresh oil.

  • Spark plug replacement

If your mower has been giving you a hard time when starting it, it means you need to replace your old spark plug. At the beginning of every mowing season, it’s a rule that you should always get new spark plugs for your mower. You can also replace the plugs after using your engine for 100 hours which will take a long time if you don’t use your mower frequently. This will ensure that your mower has a smooth start and you also get to avoid getting frustrated when using it.

  • Fresh fuel

If you’re getting your first mower, you should keep in mind that gasoline goes stale after about 30 days and this causes the stale fuel to become glued to the internal parts of your engine, especially if you’re using ethanol-blend fuel which attracts moisture. This moisture is separated from the fuel and this tends to cause your engine parts more prone to corrosion. The corrosion damage tends to reduce your engine’s overall performance. However, you can avoid all this if you treat your fuel every time you fill up your gas tank. You can also use fuel stabilizers to protect your engine from the damaging effects of ethanol and keep your fuel fresh for about 3 years.


With so many different brands and engine models, it can be very confusing and frustrating if this is your first time finding a new engine for your old one. Replacing your lawn mower engine is a simple process you can carry out at home, but the hard part is finding the best lawn mower engine that will be the right replacement for your old one. There is nothing that will kill your joy of mowing your lawn on a sunny day faster than using the wrong mower. There are many factors you need to consider before choosing an engine because it’s an essential and long-term investment and you don’t want to spend a lot of money on the wrong equipment. The Briggs & Stratton 33S877-0019-G1 single cylinder engine is a good quality engine that will not burn a hole in your pocket.

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