Makita EK7651H Review | An Exceptional 4-Stroke Power Cutter

Welcome to our Makita EK7651H Review. The only 4-Stroke Power Cutter on the market. Compared to other power cutters, it runs smoother, much easier to maintain, no oil mixing, and Much quieter than traditional 2-stroke concrete cutters at only 92.7 dB. Compare that to the Husqvarna K 760 II which is rated at around 115 dB.

In this article we delve deep at the 14″ Makita EK7651H and explain why a 4-stroke engine is far superior to the standard 2-stroke engine that other manufacturers use.

Intro | Makita EK7651H Review

According to Makita, the Makita MM4 (EK7651H), 4-stroke, 14” power cutter is the first of its kind in the world. It’s true that these power tools traditionally use 2-stroke engines and Makita has chosen to buck the trend by using a 4-stroke engine, which has taken many years of research to engineer, manufacture and design. Makita truly committed to creating a superior concrete cutter than anything else on the market.

Adam Livingston, Makita Product Manager says :

“This new 4-stroke engine power cutter runs quieter, idles smoother and is more fuel efficient,” said Livingston. “It also has several other innovative features including automatic decompression which reduces pull-starting force by up to 40%, and an all-aluminum integrated wheel kit that retracts when not in use.”

Makita have listed numerous advantages to using a 4-stroke engine instead the usual 2-stroke engine. Though this begs the question: why have most power tool manufacturers always preferred 2-stroke over 4-stroke engines for handheld machinery?

Has Makita reinvented the 4-stroke engine, or have the old assumptions been proven wrong?

I’m going to seek to address these questions. Firstly by reviewing the Makita EK7651H alongside two of the most renowned 2-stroke equivalents, the Makita EK6101, and the Husqvarna K760 II. These are some of the best power cutters on the market and both brands have massive respect in the industry.

The Makita EK7651H review is intended to give you the full picture. Not only will I be looking at every detail of this very impressive machine, but also try to uncover why they have chosen to replace the 2-stroke engine with a 4-stroke variant. I’ll, therefore, be addressing the old 2-stroke vs 4-stroke debate through the course of the review.

VIDEO | A Closer Look at the Makita EK7651H Power Cutter

One of the main reasons why handheld, gas-powered tools have opted for the use of 2-stroke engines is the improved power to weight ratio. Have modern, lightweight alloys changed the scenario? Perhaps to some degree, lightweight materials have made a difference. But in reviewing the Makita EK651H, and comparing it to the 2-stroke power cutters, you’ll see that the Makita EK651H has a larger capacity engine than the other two. It is also heavier, yet the EK7651H has the lowest horsepower. So the power to weight ratio is highly unfavorable, when comparing the 4-stroke Makita EK7651H to the 2-stroke power cutters. This doesn’t bode well for the 4-stroke machine. But is it really that simple?

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2-Stroke vs 4-Stroke Engine –— The Real Story

Before I begin with the Makita EK7651H review, we should address the elephant in the room: why the 4-stroke engine?

There are many articles that will explain how 2-stroke and 4-stroke engines work, so I’m not going to go into much detail about all that. The main difference, to you the user, is that a 2-stroke engine does not use valves and is lubricated by adding oil to the fuel. There are pros and cons to both.

Because a 2-stroke engine is less complicated mechanically, it weighs less. These engines also produce more power, relative to their engine size, when compared to 4-stroke equivalents. However, the maximum power output of a 2-stroke engine is achieved at a much higher RPM. These engines lose power drastically as the RPM is reduced. So if the engine becomes bogged down, in other words it suddenly has to work harder, your power drops away very quickly.

So the power advantage of a 2-stroke engine is a double-edged sword. You have a lighter engine with more power, but you need to keep the engine RPM high at all times. This takes its toll on the engine. A higher RPM means more friction. This generates more heat and greater wear on the engine. It’s a common fact that 2-stroke engines don’t last as long as 4-stroke engines. Though, because they are less complicated, 2-stroke engines are cheaper and easier to repair. So there are benefits and disadvantages to both engine types when it comes to long-term maintenance.

The excessive carbon produced by 2-stroke engines is probably the biggest argument in favor of 4-stroke engines. This is of particular importance now that carbon emissions have become such a contentious issue. There are environmental concerns relating to 2-stroke engines and this is a heated topic amongt environmental agencies, like the EPA and CARB. There are some that have proposed the phasing out of 2-stroke engines altogether because of their lousy emissions.

VIDEO | 2-Stroke vs 4-Stroke Engine

Apart from the environmental concerns, high-carbon 2-stroke engines have a maintenance drawback. The spark plug, combustion chamber, and carburetor become clogged by the sooty carbon buildup. This means more frequent maintenance is required and it has an impact on the engine life. The need to mix oil with the fuel is also a hassle that some would rather avoid. You’re using a lot more oil for a 2-stroke engine, so this increases your daily running costs.

Another argument in favor of the 4-stroke engine is noise levels, 2-stroke engines are notoriously loud screamers. A 4-stroke engine is always much quieter. It is also more fuel efficient than a 2-stroke engine. 2-Stroke engines tend vibrate a lot, so a 4-stroke engine is usually more comfortable with less user fatigue. In the end, this increases productivity as you can work for longer without stopping to rest your arms.

Using a recoil starter on a 2-stroke engine has always been easier. Because of the lower compression, it doesn’t take as much effort to pull on the cord to start these engines. Though manufacturers of 4-stroke engines have eliminated this problem by fitting valve decompression mechanisms to make their engines easier to start. This does, however, add a little extra weight to an already heavier engine.

So the only real benefit to using a 2-stroke engine is the weight factor. Since you’re holding that weight whilst using the machine, this is a compelling reason to opt for the, lighter 2-stroke option. Even with the best metal technology, this will always be true. A 2-stroke engine will be lighter than any 4-stroke engine of the same capacity. The power advantage is debatable. I prefer the low end torque capabilities of a 4-stroke engine. Sure, a 4-stroke engine won’t have the same maximum HP as a 2-stroke engine with same CCs. But, you have more usable power across the rev range when using a 4-stroke engine. A 4-stroke engine will continue to deliver a reasonable amount of power, even when the RPM drops really low.

When you’re using a power cutter and you suddenly encounter a denser material, the engine will immediately slow down. In this situation, a 4-stroke engine may groan and lose performance, but it will keep on cutting. A 2-stroke engine will stall very easily. Even if it keeps running, the 2-stroke engine will have virtually no power. So, when the 2-stroke engine loses RPM, you have to stop, pull the blade out of the material and use the throttle to increase the RPM before you can continue cutting.

Since you’re paying more for the 4-stroke engine, it all comes down to one important question: is the Makita EK7651H worth the higher price? Like I said earlier, you have to contend with a heavier machine. Though in terms of economic value, the 4-stroke engine makes better sense. It’s going to last much longer and won’t need to be repaired as often. Your running costs are lower, because you’re not burning through oil on a daily basis and a 4-stroke engine uses less fuel. In the long run, a 4-stroke engine is going to cost you much less than a 2-stroke engine and you have less downtime. The reliability of a 4-stroke engine means that you won’t be stopping regularly to clean a spark plug or the carburetor. In the end, for a contractor, time is money.

✓ Learn more by reading our comprehensive article : 2-Stroke vs 4-Stroke Engine : What’s the Difference?

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Makita EK7651H MM4 Review

The first 4-Stroke concrete cutter on the market.

Ideal for landscapers, road construction crews, railroad crews, rescue crews, general steel contractors, masons, and welders.

Best concrete power cutter for the money. The 4-stroke engine makes it much quieter, more efficient and easier to maintain than other concrete cutters.

Features :

• Automatic engine decompression valve is engineered into the cam gear to reduce pull-start force by 40%
• Pressure compensated carburetor with vented choke plate allows for optimum fuel delivery and reduces the occurrence of flooding during cold starts
• Integrated all aluminum wheels reduce fatigue during long straight cuts and retract when not in use to prevent unexpected movement
• Eliminates the need for separate mixed oil/fuel can
• Lower noise at 92.7dB(A) and smoother idle for continuous operation
• Five-stage, foam-paper-nylon filtration system with advance direction air flow provides cleaner air for better engine durability
• Lower fuel consumption at .45 gallons per hour
• Reduced exhaust and intake carbon build-up for long cylinder life
• Three ring piston for improved commercial engine durability
• Clear primer bulb facilitates fuel delivery to the carburetor for easier cold starts
• Advanced oil separation and lubrication system to improve valve train durability and engine life
• Specially treated rods, followers and valves minimize wear and extend engine life
• Single lever On-Off-Choke operation switch for operator convenience
• Shielded exhaust outlet and larger spark arrestor screen prevents contaminates from restricting air flow
• External fuel tank vent eliminates pressure build up
• Sealed cartridge recoil starter rope reduces wear by keeping out dust and debris
• Cutting arm easily changes from center position to flush (outboard) position allowing cuts directly adjacent to curb edges, wall or directly above the ground
• Cushioned operator grips with 4 vibration-absorption rubber buffers for increased operator comfort
• Convenient oil level check and easy oil maintenance for longer engine life
• Easy access carburetor for more convenient repair and maintenance
• Replaceable tank fuel filter is easily accessible without special tools
• Included water kit with quick release attachment is adaptable to most common hose threads

Documents for the Makita EK7651H :

• View or download the MANUAL
• View or download the BROCHURE
• View or download the PARTS
• View or download the MAINTENANCE SCHEDULE

Features:

Now onto the headline news, the Makita EK7651H review. Having looked at the pros and cons of the 4-stroke engine, you can decide for yourself if the Makita MM4 is a better power cutter than the traditional 2-stroke variants. When it comes general quality and usability, this is a true Makita product. In a nutshell, excellent. This is a brand that has won my admiration over many years of using power tools. I truly believe that Makita engineering is amongst the best in the world. They also make no compromises when it comes to using the very best, most durable materials. These machines just don’t quit on you.

In keeping with the Makita reputation for ultimate durability, the 75.6cc engine is about as tough as it gets. Three engine rings, along with lower carbon, means that you’ll get years of reliable service before there’s any sign of engine wear. The valves, rods, and followers are treated for an extra heavy-duty life cycle. They also use one of the best air filtration systems, which is a massive advantage when cutting concrete with all that fine dust being emitted.

A cyclonic air intake has proven itself as an excellent way to extend filter life, Husqvarna have been doing it for years and it really works. Makita have done even more to ensure better reliability and engine durability by using a 5 stage air filter in addition to the very efficient cyclonic air intake. Basically, cyclonic air intake systems separate the heavy debris before it can reach the air filter. For even better engine life, Makita have developed an improved oil separation and lubrication system which does a lot to reduce engine wear over time.

This is probably the most fuel efficient 14” gas power cutter on the market, with an amazing 0.45 gallons per hour. The gas tank isn’t that big, 37 Oz. This gives you a little over half an hour of continuous runtime, which isn’t bad at all.

Using the Makita EK7651H is a really great experience. Automatic decompression, a clear primer bulb, and an easy to use single lever on, off, choke control, takes all the hassle out of getting the engine started. Not to mention, no need to mix gas and oil. Along with a very smooth running engine, they’ve include four vibration dampers and very comfortable handles with a perfectly positioned throttle trigger. It also has retractable, ultra-tough aluminum wheels. Long straight cuts are made much easier, with the safety benefit of no wheels when they aren’t needed.

Although a gas power cutter is never going to be a quiet machine, the Makita EK7651H probably has the lowest noise levels compared to any other: 92.7dBA. This is about 5dB lower than the Makita 2-stroke 14” power cutter. The difference is quite noticeable, even if it doesn’t look like much on paper. Changing the cutting arm position from center to the outboard (flush) position, is as easy as it gets, saving valuable time. Dust suppression is effortlessly taken care of, using a water kit with a quick release hose fitting.

The advanced technology used to make the Makita EK7651H engine more durable also considerably reduces your need for extra maintenance. When the need for routine maintenance arises, everything is made much easier. The replaceable fuel tank filter is quick and easy to access. The carburetor is also very easy to access.

When we look at the power specs, the Makita EK7651H may appear to be the underdog in this race. Maximum horsepower is a little lower than the other two in this review – 4.1 HP (3 KW). The maximum no load spindle speed is lower, 9100/4300 RPM. Though if you read the pros and cons of 2-stroke vs 4-stroke section of the article, you’ll see that this is not essentially a bad thing. As you cut through concrete, for example, you’re going to move through dense sections of aggregate and lighter materials. The 4-stroke engine is going to handle these power transitions with much more ease than a 2-stroke engine. This won’t be as serious when cutting metal which tends to be more uniform in density. The Makita EK7651H has a slight weight disadvantage when compared to the 2-stroke power cutters. Though the weight is still very reasonable at 28-pounds (dry weight).

The Makita EK7651H is a work of pure genius when you look at how tough and durable it is. The effort that has gone into building one of the most enduring and reliable engines for a power tool is astounding. I’ve always expected the very best from Makita. But this time, I think they’ve exceeded even their own reputation for superb engine technology. Lower fuel consumption and noise levels are a much appreciated bonus and this is a wonderful power cutter to use. In my opinion, it will take a lot to beat this beast of a machine. Makita after sales service also ranks amongst the best in the industry. So peace of mind is part of the deal.

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Makita EK6101 2-stroke

14-Inch, 61cc — Excellent 2-cycle Power Cutter weighing only 19.6 lbs. 

Ideal for : metal decking, angle iron, i-beams, cast iron pipe, brick/masonry, stone/concrete blocks, railroad rails, road curbs, and asphalt.

Features :

• Cyclonic air Intake delivers more air, more efficiently and increases air filter life by discarding 90% of larger debris
• Start capacitor with start support function resulting in significantly less pull start force
• Smaller hub and drive wheel assembly increases maximum cutting depth to 5-1/8″
• Stratified Air Scavenging (SAS) sends air flow through the transfer port to push the burned gases through the exhaust outlet recovering 75% of unburned fuel and reducing fuel consumption by 20%
• Larger surface inverted intake and filter system extends filter life and service intervals
  Sliding front engine mounts help absorb vibration by detaching when cutting pressure is applied
• Multi-ribbed, self tensioning belt is engineered to provide a more consistent transfer of power
• Lower noise at 97 dB(A) and smoother idle for continuous operation
• Clear primer bulb facilitates fuel delivery to the carburetor for easier cold starts
• On-Off choke operation switch on a single lever with touch-stop function for operator convenience
• Aluminum guard and wheel pressure plates to reduce overall weight
• Clear fuel tank window provides a convenient fuel level indicator
• Water supply kit with pressure control knob for more accurate flow rate adjustments
• Vertical filler neck position for conventional refueling operation
• Integrated wrench holder

Documents for the Makita EK6101:

• View or download the MANUAL
• View or download the BROCHURE
• View or download the PARTS

Overview

When comparing the 2-stroke Makita EK6101 to the newer Makita EK7651H, the 2-stroke has the advantage of being lighter and cheaper. But this is about all that places the EK6101 at an advantage. While the 2-stroke power cutter is most certainly a high-quality machine, the older technology is by no means a match to the truly amazing EK7651H. Apart from the fact that a 2-stroke engine will never be as reliable and durable as a 4-stroke engine, the EK6101 does not have all the advanced technology that makes the EK7651H such a remarkable machine.

The Makita EK6101 61cc engine is, in the context of 2-stroke engines, quite remarkable. Fuel consumption is improved by the use of a Stratified Air Scavenging (SAS) system. This recycles unburned exhaust gasses which is said to improve fuel consumption by as much as 20%. It also uses the same cyclonic air intake which reduces dust in the filter and improves engine durability. The inverted filter, with a larger surface is great, but is not nearly as effective as the 5 stage filter used for the EK7651H, 4-stroke engine. The 2-stroke engine has an impressive power spec, 4.4 HP (3.2 KW), with a max no load speed of 9850/4400 RPM. You’re using a 50:1 fuel to oil mixture, so it’s quite economical when it comes to 2-stroke oil consumption.

The Makita EK6101 is easy enough to start with a starter capacitor, fuel primer bulb, and convenient on, off, choke lever with one touch stop. The fuel tank is even smaller than the Makita EK7651H, at 23.6 Oz. I don’t have fuel consumption specifications for the 2-stroke Makita, but I’m pretty sure it is thirstier than the 4-stroke machine. My guess is that you won’t have very long working times between refueling stops. At least they’ve provided a clear fuel tank with an easy to use filler. So you know when it’s time to fill the tank and you won’t be splashing gas all over the place when you do.

The Makita EK6101 doesn’t have wheels. Instead it has pretty easy glide rubber buffers at the base. I suppose, since this is a lighter machine (19.6 LBS), it’s not too much of an inconvenience. The self-tensioning, multi-ribbed belt is great and makes for a consistent power transfer. The Makita EK6101 is not quite as comfortable to use as the EK7651H in terms of vibration. None the less, the sliding front engine mount does a lot to negate this.

Cutting depth is improved by the use of a smaller hub and drive assembly, giving you a maximum depth of 5¹⁄₈”. It has a fantastic water system with a flow valve which lets you control how much water you use. At 97dBA, this is most definitely a loud machine. Though when compared to most 2-stroke power cutters, this is not bad.

Because this is a Makita tool, I know that quality and durability is a given. Perhaps some of the advanced technology used for the Makita EK7651H makes it a more durable machine. But I can’t say that the 2-stroke power cutter is inferior to its competitors from other brands. It has the obvious 2-stroke issues, like regular spark plug and carburetor cleaning, along with some extra noise and vibration. But, no matter how advanced your engineering is, there are some aspects to 2-stroke engines that can’t be avoided. In the end, this is a lightweight and very powerful machine. That’s something we all can appreciate. The Makita name also counts for a lot, as far as I’m concerned.

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Husqvarna K760 II — 2-stroke

One of the best selling 2-stroke concrete cutters on the market.

Applicatons and Uses : Adjustment to openings. Asphalt, Blocks, curbstones and pavers, Burying of cables, Cast concrete, Floors and walls, Pipes, Rails, Rescue cutting.

Features:

• A light, compact and powerful machine with superior power-to-weight ratio.
• Vibrations below 2.5 m/s2 in the cutter handles for more comfort and longer operation periods.
• A strong Poly-V belt combined with our maintenance-free starter DuraStarter and efficient filter-system Active Air Filtration ensures long service intervals.
• Unique design of the carburetor, cylinder and digital ignition system, together with air purge and decompression valve ensure an easy start.
• Easy to change blade guard position
• Less slurry and low water consumption : . A progressive water valve for exact adjustment of the water volume to efficiently bind the dust and reduce slurry.
• Fits multiple blade bushings : Blades with 20mm and 25.4mm bore can be fitted thanks to the reversible blade bushing.
• DualCharge : Provides more power, lower fuel consumption and greatly reduced emissions.
• Blade retarder : Reduces the stop time of the blade when the machine is switched off, which enables you to quickly move on to the next job.
• Maintenance-free starter
• Reduced wear : drive belt with fully sealed transmission, which keeps out the cutting dust.
• Cuts close to walls or ground : cutting arm is reversible which lets you cut closer to walls or the ground. T
• Active Air Filtration : Two-step filtration system with centrifugal cleaning and a single paper filter increases product life and extends service intervals.
• Anti-vibration system : Distance between the handles is large to enable the user a comfortable operating position and to reduce strain. The handles and the short engine body mean the user always stands close to the machine, for easier handling and control.
• DuraStarter : Virtually maintenance free starter, thanks to the dust-sealed starter and the durable starter cord
• EasyStart : Easier starting by reducing the compression in the cylinder.
• SmartCarb : Automatic filter compensation maintains high power during the air filter life time.
• Constant-flow water valve : integrated regulator controls the water volume, ensuring a constant flow to the blade. It also ensures the amount of water is sufficient to bind the dust without creating an excess of water.
• Control panel : Light-emitting diodes indicate the direction of rotation on the control panel, while the raise and lower speed, and the advance are controlled by the potentiometers on the handlebar.

Overview

When it comes to reliable, durable 2-stroke engines, Husqvarna have certainly paid their dues. There can be no doubt that the Husqvarna K760 II can stand proudly amongt the very best 14” power cutters. Compared to the Makita EK7651H and EK6101 models, the Husky is the most powerful. For those of you who may be familiar with the previous generation K760 model, the K760 II is a more powerful version of the original. It has a larger engine, with more horsepower, and has a larger 14” blade.

The 73.5cc X-Torq engine, used to power the Husqvarna K760II, is a technological marvel. As far as 2-stroke engines go, it is remarkably smooth, with elusively low vibration levels. Producing a staggering 4.9 HP, it outperforms most 14” gas power cutters. Husqvarna Active Air filtration has been a game changer in the industry and has been imitated by many power equipment manufacturers. The centrifugal air intake functions in the same way as the Makita cyclonic air intake, they just use different terminology to describe the same principle. Heavy debris is forced outward while only fine dust makes its way to the center where it passes through the paper air filter.

Overall performance and reliability are drastically improved by the Husqvarna SmartCarb, with a built-in filter compensator. Basically, it keeps the fuel to air mixture at an optimum as the airflow is reduced due to buildup in the filter. Digital ignition, together with the ultra-tough dura starter make the Husqvarna K760 II one of the easiest machines to start. Fuel consumption is also one of the best for a 2-stroke engine of this size – 460g/KWH. The Husqvarna X-Torq also uses a 50:1 oil to fuel ratio, for the most economical use of 2-stroke oil. The reasonably sized, 31.7 Oz gas tank, should provide better working time (per tank of gas) than the 2-stroke Makita. But I doubt that it will match the Makita EK7651H, which is probably more fuel efficient and has a larger tank.

The engine can reach a maximum of 9300 RPM, with maximum power output being produced at 9000 RPM. Maximum output at the shaft is 4300 RPM, this is 100 RPM less than the 2-stroke Makita, but with ½ HP more power. The Poly-V belt appears to be very similar to the Makita equivalent, with great power delivery and durability. The Husqvarna K760 II has an excellent dust suppression / slurry system with a valve to regulate the water flow.

The handles are positioned for great control, and the anti-vibration system keeps the vibration level below 2.5 M/s². It’s a remarkably comfortable machine to use. The cutting depth is fairly standard for a 14” power cutter at 4.92”. Though this is not quite as impressive as the Makita EK6101. It’s easy to adjust the multiple blade positions for various types of cutting. One thing that should be pointed out is that this is very noisy machine, with noise levels reaching 115dBA (approximately 101dBA at the operator’s ear).

The Husqvarna K760 II, like the two Makita machines that we’ve reviewed, is a very competent professional-grade power cutter. It isn’t easy to say which the ultimate of the three is. Though the power advantage provided by the Husqvarna is notable and very impressive. The Husqvarna X-Torq engine is, arguably, one of the very best. With proven reliability and exceptional aftersales service, the Husqvarna brand has earned much recognition and praise. So there are any number of reasons why some may prefer the Husqvarna K760 II over any of the others.

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Learn more by reading our article entitled :

• Best Concrete Saw : Choosing the Right Concrete Saw
• Husqvarna K760 and Other Concrete Chainsaws
• Buying A Concrete Chainsaw