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Although most small tools like chainsaws, string trimmers and blowers still use 2 cycle engines, they have pretty disappeared in larger tools like lawn mowers and snow blowers. This I suppose was mostly due to the EPA tightening requirements for pollution and noise reduction, but improvements have been made in 2 stroke engine design that could meet these requirements. There are many advantages in 2 cycle engines over 4 cycle engines, including lighter weight, simplicity, higher specific output, reduced maintenance and lower cost.

So, my question is that if a 2 cycle lawn mower were to become available, would you buy one ?

lighter weight, simplicity, higher specific output, reduced maintenance and lower cost.

Frist of all I am not that familiar with 2 cycle lawn mower engines in lawn mowers. I have owned snowmobiles, and motorcycle with them. Frist of all a well made 2 cycle engine isn't that much different in weight then a 4 cycle as I can see. Pulling one out of the front of a snowmobile them 2 cycles aren't light. Simplicity ? They can be very temperamental in running. Only thing missing is the valve system. Higher output yes they get there power at a lot higher RPM. As I understand a lot of the motocross racers are going to 4 cycle now and wining races. reduced maintenance, It sure seem like we were always working on them 2 cycle engines in the snowmobiles and bikes. They would just shake themselves apart or burning up pistons if the fuel mixture was wrong. Low cost, parts aren't any cheaper for a 2 cycle then a 4 cycle. I own two scooters with 2 cycle engines but find the newer 4 cycle scooters get a lot better gas mileage. I am also saying maybe a mower is a lot different then a snowmobile or bike??

reynoldston said:

lighter weight, simplicity, higher specific output, reduced maintenance and lower cost.

Frist of all I am not that familiar with 2 cycle lawn mower engines in lawn mowers. I have owned snowmobiles, and motorcycle with them. Frist of all a well made 2 cycle engine isn't that much different in weight then a 4 cycle as I can see. Pulling one out of the front of a snowmobile them 2 cycles aren't light. Simplicity ? They can be very temperamental in running. Only thing missing is the valve system. Higher output yes they get there power at a lot higher RPM. As I understand a lot of the motocross racers are going to 4 cycle now and wining races. reduced maintenance, It sure seem like we were always working on them 2 cycle engines in the snowmobiles and bikes. They would just shake themselves apart or burning up pistons if the fuel mixture was wrong. Low cost, parts aren't any cheaper for a 2 cycle then a 4 cycle. I own two scooters with 2 cycle engines but find the newer 4 cycle scooters get a lot better gas mileage. I am also saying maybe a mower is a lot different then a snowmobile or bike??

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The reason a motorcycle or snowmobile 2 cycle engine is as heavy as a 4 cycle is that they are now water-cooled, although they are still lighter than the larger 4 cycle water cooled engines that produce comparable power. 450cc 4 cycle MX bikes can compete against 250cc 2 cycle MX bikes and 250cc 4 cycle MX bikes against 125cc 2 cycle MX bikes. Also, 4 cycle MX engines are much harder to hot restart than 2 cycle ones after a rider falls and stalls the engine, which is why some riders still prefer them. As to mileage, it is comparable between engines producing the same power, so a 450cc 4 cycle will use about the same amount of gas as a 250cc 2 cycle.

Anyway, lawn mower engines are smaller and produce less specific power than MX racing engines, so they don't need to be water cooled, which reduces weight, maintenance and cost. They can be tuned to produce power and torque at lower RPMs to reduce fuel consumption and make suitable for lawn mower use. LawnBoy used to make very good 2 cycle mowers, but chose not to upgrade their engines to meet current more stringent EPA requirements. I have two handheld leaf blowers with 2 cycle engines that are clean, quiet and very easy to start/restart, so I don't see why this is not possible with the slightly larger displacement engines that would be needed for walk behind mowers.

No I wouldn't buy one.

But if I owned a considerable amount of stock in a major spark plug manufacturing company, a recoil starter rope company and chiropractic clinic I'd certainly promote their sales.:laughing::laughing:

SandburRanch said:

No I wouldn't buy one.

But if I owned a considerable amount of stock in a major spark plug manufacturing company, a recoil starter rope company and chiropractic clinic I'd certainly promote their sales.:laughing::laughing:

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:laughing::laughing::laughing:

SandburRanch said:

No I wouldn't buy one.

But if I owned a considerable amount of stock in a major spark plug manufacturing company, a recoil starter rope company and chiropractic clinic I'd certainly promote their sales.:laughing::laughing:

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As far as weight goes I am talking air cooled snowmobile engines. Not light when you have have to lift a two or three cylinder 2 cycle engine out of the front of a snowmobile hood. Yes back in the early day I agree with the spark plugs, recoils and chiropractic clinic. I have found with the newer lubrication's this isn't true anymore when you can run 50 to1 oil. I am running mine 100 to 1 with Amsoil. I find the plugs and starting is just as good as any 4 cycle engine with a well tuned engine. Now don't get me wrong I am not a 2 cycle fan. They still stink and you smell like oil after being around one very long. Some people say they like the sound of a two cycle but to each there own on that I just happen to perfer the sound of a 4 cycle HD motorcycle.

reynoldston said:

Now don't get me wrong I am not a 2 cycle fan. They still stink and you smell like oil after being around one very long. Some people say they like the sound of a two cycle but to each there own on that I just happen to prefer the sound of a 4 cycle HD motorcycle.

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My recent experience with two 2 cycle blowers when run with 50:1 TruFuel premix is that they don't smell of oil or leave any oil on the blower and certainly not on me. There is also no visible exhaust smoke. After use I don't smell gas or oil in the garage from them either. Whether that is due to the small size of the engines or the synthetic fuel I'm not sure, but it's certainly not a problem.

I don't particularly care for the sound they make, but it's not a problem because they are very quiet, even at full throttle, and I don't need ear protection when I use them.

I do wholeheartedly agree with you that the thunderous sound of a good running Harley is sheer pleasure :biggrin:

Nice looking bike. When I frist looked and seen the air cleaner I was thinking Sportster but then looked a little closer and then changed my thought to Dyna. My self I have a XL883C. I am not mowing grass with a 2 cycle mower. This is following a off road 2 cycle bike or snowmoble all day. Not the same must be. I was just thinking walking in back of a lawn mower you would also pick up the smell??

I love the smell and sound of 2 cyl everything. A question, can and do 4 cyls have a powerband like the old 2 cyl dirtbikes?

SandburRanch said:

No I wouldn't buy one.

But if I owned a considerable amount of stock in a major spark plug manufacturing company, a recoil starter rope company and chiropractic clinic I'd certainly promote their sales.:laughing::laughing:

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Does anyone even make a two stroke lawn mower engine anymore? I surely wouldn't buy one.

Ric said:

Does anyone even make a two stroke lawn mower engine anymore? I surely wouldn't buy one.

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Yeah I'm not sure. I think Lawn-Boys are now 4-stroke. At least I hope, because I used one for a couple lawns once and used just plain gas!

lawn mower fanatic said:

Yeah I'm not sure. I think Lawn-Boys are now 4-stroke. At least I hope, because I used one for a couple lawns once and used just plain gas!

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Yeah there 4-stroke, there owned and made by Toro now and to my knowledge Toro doesn't make and never has made a 2-stroke.

Toro commercial push mower 2 cyl Suzuki.

If some company like Toro or MTD or the like came out with one with a Tec engine even if it was a Chinese copy I would go to the dealer and order it and wait for it to arrive.

Absolutely, I still use 2 cycle lawnboy mowers on a daily basis. They are between 10 and 30 years old, you can’t kill them

The absolute best mower engine ever made was & still is the Victa power torque
And the numbers of them ut there 40+ ears old & still going strong is a testiment to them.

In 1984, I bought a Toro with the 2-cycle Suzuki engine.

I would buy another in a heartbeat, except...the one I have still works fine.

two cycle equipment is to much work keeping it running.

Flintmotorsports said:

two cycle equipment is to much work keeping it running.

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What goes wrong with them that doesn't go wrong with a 4-cycle engine?

two cycle equipment is to much work keeping it running.

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Quite the opposite on my end.

My parents bought a brand new Huffy mower with that typical Clinton engine which was also used on small boats. This was back in 1955 when they moved into their new home with my older brother. It mowed without problems, until I left the country in '86. It mowed well beyond that. It used reed valves which kept it economical and powerful within the powerband necessary for mowing. I don't see any reason for a lawnmower to operate on four cycles, except to comply with emissions which is rediculous, judging by how pollution isn't contained within a country's borders. If governments were serious about reducing pollution altogether, they would be working on reducing world population.
An air pollution map:



Deforestation doesen't help matters, either

I wish more people could see these maps. Thanks for posting them.

Flintmotorsports said:

two cycle equipment is to much work keeping it running.

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The simple rule with 2 strokes is to starve the engines off.
Doing that will ensure they start easily & reliably .
Killing the ignition loads up the plugs which is fine for a hot start but will make cold starts very difficult.

cpurvis said:

I wish more people could see these maps...

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There's a map somewhere showing where all the plastic which lands in the sea comes from. The same government who's pushing the environmental excuse is the same one outsourcing jobs to those polluting countries

Yes I would buy one,just bring back Lawnboys.

cpurvis said:

I wish more people could see these maps. Thanks for posting them.

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I wish before that the people who make these maps would be a tad more accurate.
3/4 of Australia has been desert for 60,000 years according to the legends of the people who were here before the white men came with axes & saws.
1/3 of the USSR was steppes so no deforestation there either.
China is chopping down their Pawlona forest at a massive rate to supply them & Japan with disposable chopsticks.
India which again had very large areas of desert / grasslands is loosing forests to broadacre agriculture faster than they are replanting and Pakastan has deforested so much they are suffering massive mudslides each & every monsoon season.

If the Global warming advocates produced literature that was believable then more people would believe them and governments could be forced into actions.
But while they continue to throw out stuff that is obviously totally inaccurate to being downright fictious they get little credibality so can be easily and logically denied.
Telling people that the oceans will rise 15 meters might be a good scare tactic if you own waterfront land but like the religious zealots who keep telling people the second coming will be on a particular date.
When it does not happen no one believes them or any one else touting a similar story.

The fact about 2 strokes & pollution that over the like cycle of the mower, they create about 1/3 of the pollution that 4 strokes do and in particular the new EPA compliant lean burn engines that run very hot and wear out very fast.
However the self serving saviours of the planet choose to ignore oil that the 4 stroke burn & oil that is removed from a 4 stroke sump. They also ignore embedded pollution created during the manufacture of the mowers and the embeded pollution in the logistical chain that gets the mower to your front door.
So the only pollution in their tiny closed minds is what comes out the exhaust pipe.
For those mowers that discharge the exhaust under the base plate, mush of the heavier parts of the exhaust gas and in particular the unburned oil combines with the grass clippings and is biologiclly decomposed along with the clippings and there is some work that suggest that these clippings compost faster & better than the clippings from a 4 stroke , but that is way too complicated for the tiny minded to comprehend.

lawn mower fanatic said:

:laughing::laughing::laughing:

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:laughing::laughing::laughing:

bertsmobile1 said:

...1/3 of the USSR was steppes so no deforestation there either.
China is chopping down their Pawlona forest at a massive rate to supply them & Japan with disposable chopsticks...

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As Russia was just a republic of the entire USSR, the border between them and China was enforced. Since the dissolvement of the USSR, corruption and indifference on the part of the Russiam government has led to unbridled illegal deforestation and poaching. As soon as the Russian government diverts its attention from jailing political dissedents to using that energy for imprisoning corrupt border guards and for shooting poachers as well as illegal loggers on sight, they would automatically have fewer political dissidents.
Yes, that particular map is somewhat inaccurate, because it fills in the entire country with color, instead of only coloring the particular area which is getting deforested. The map also doesen't take into account historical deforestation carried out by ancient Romans in what's now former Yugoslavia and Albania as well as Native Americans deforesting parts of the southwest of that country, as well as that done by colonialists worldwide, just to name a few

bertsmobile1 said:

...the unburned oil combines with the grass clippings and is biologiclly decomposed along with the clippings...

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That's fine, if you're mixing SAE 30 salad oil into the fuel. Our old 1955 Huffy mower recommended using strictly SAE 30 non-detergent mineral oil. Well, the mower itself didn't. The sticker glued in plain sight on the mower did. Why non-detergent is still beyond my ability to comprehend this. My worry would be more the compostability of modern synthetic and half-synthetic oils, in countries where non-detergent SAE 30 mineral oil is simply unavailable

Fat_Bollocks said:

That's fine, if you're mixing SAE 30 salad oil into the fuel. Our old 1955 Huffy mower recommended using strictly SAE 30 non-detergent mineral oil. Well, the mower itself didn't. The sticker glued in plain sight on the mower did. Why non-detergent is still beyond my ability to comprehend this. My worry would be more the compostability of modern synthetic and half-synthetic oils, in countries where non-detergent SAE 30 mineral oil is simply unavailable

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Actually you are way off.
Oil is just carbon or rather the excriment of bacteria .
It is a NATURAL product and will happily NATURALLY decompose in the enviroment.
In fact there is around 300 different bacteria that thrive on oil so SMALL or Dilute oil spills are not a problem and about 20 fungii .
It has been demonstrated that you can plant fungaii spores into oil contaminated soil and they thrive.
Further more cattle can eat the fungaii and they thrive.Only downside is time, it takes several years before all of the spilled oil is consumed.
LARGE oil spills are a problem because there is a fixed rate that nature can decompose oils and different crudes decompose at different rates.

You can run most modern 2 strokes on strait canola oil or caster oil for that matter.
Even better is to use vegie oil in our chainsaws oil tank.
The down side of this is the bacteria in the oil soaked swarf can cause a spontanius combustion event.

Most self appointed enviromental crusaiders , while being very passionate, have no understanding of science.
his is why I cancelled my life subscription to Greenpeace.
The scientists got elbowed out by the humanities graduates and the whole shebang became a medium for expansion of egos that were already way too big to start with.

There is a weird idea that anything & everything man made or modified is absolute poision to the enviroment and everything "natural" can do no damage.
Too much water is every bit as dangerous as too much oil

Fat_Bollocks said:

. Why non-detergent is still beyond my ability to comprehend this. My worry would be more the compostability of modern synthetic and half-synthetic oils, in countries where non-detergent SAE 30 mineral oil is simply unavailable

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That is because you have no understanding of the chemistry of oils.
As there is no filter on most mowers there is no need to keep all of the particulates in fine suspension totally encaapsulated by the detergent molecules to allow for quick & easy removal.
Further more mower oils contain a lot more anti-corrosion chemicals , water dispersants & anti skuf metal oxides ( zinc usually ).
Keeping all of these in the oil is difficult when the detergent content is high.

bertsmobile1 said:

...Most self appointed enviromental crusaiders , while being very passionate, have no understanding of science.
his is why I cancelled my life subscription to Greenpeace...

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Those organizations start up with benevolent intention. But, over time, many of them get corrupted. American trade unions are a prime example of this, differing from environmentalist groups in that the trade unions mentioned were infiltrated by organized criminals. These other humanitarian organisations become aware that once an environmental problem is solved, there would no longer be a reason to donate to these organizations. Therefore, they would have to disband and their administrators would suddenly be left without income

bertsmobile1 said:

... crusaiders...

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:laughing: You even write with an Australian accent, Mait

Fat_Bollocks said:

Those organizations start up with benevolent intention. But, over time, many of them get corrupted. American trade unions are a prime example of this, differing from environmentalist groups in that the trade unions mentioned were infiltrated by organized criminals. These other humanitarian organisations become aware that once an environmental problem is solved, there would no longer be a reason to donate to these organizations. Therefore, they would have to disband and their administrators would suddenly be left without income :laughing: You even write with an Australian accent, Mait

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No spell checker on the computer & I am a 40wpm typist on a good day.
I don't think it is a case of consultants disease, just a case of cherry picking "cute " causes or becoming obsessed.

hazelwood power station down here is a perfect example.
The "office dwelling greenies" are hell bent on closing it down.
It sits on top of the largest deposit of brown coal ion the planet.
Scientists want the brown coal gassified ( in fact all coal should be gassified before being burned but that is a different story ) , then the existing power station converted to direct gas turbines.
Thus thousands of tons of steel towers and hundreds of tons of copper wire, tansformers etc all remain in use.
The byproducts of the gassified coal are all valuable inputs to the chemical industry so again more employment.
Even better is the effluent from Melbourne ( 3.5 million people ) could be membrane processed into industrial grade water to feed the turbines thus solving Melbourne's lack of water problems.
The water processing is directly scaleable so could be used to balance the grid.

But no the greenies are getting their way and the plant is closing , hundreds will be out of work & electricity will become 30% more expensive so more people will use wood fires to heat their homes therefore subsantially increasing the overall pollution.

Ric said:

Yeah there 4-stroke, there owned and made by Toro now and to my knowledge Toro doesn't make and never has made a 2-stroke.

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Lawnboy is part of Toro.
Toro has made 2 stokes but they don't any longer.

I have owned a few two stroke mowers and I would prefer to not own one again. One was a Lawn boy and the other a toro. The Toro was a very nice mower, but not because it was a two stroke. I say that inspite of it being a two stroke. It had an aluminum deck so rust would never be an issue.

Two strokes require mixing gas. You usually need to use higher octane gas. Some reiquire 89 octane and some even higher. They do smoke more than a 4 stroke even if they improve them they will still smoke more and drink e gas faster. That alone makes them pollute more.

The weight difference is not a big deal on most walk behinds. If you have a heavy mower or have some imparement you can always get a self propelled.

It is a pretty easy decision for me.

The only real benefit would be if you have to mow a hill of any size. And I do not.

Smoke is not the only pollutant that comes out of an engine, two stroke or four strokes.
The dangerous stuff is what you can not see.
When doing emission tests the primary focus is on unburned hydrocarbons and then on Carbon monoxide & dioxide.
They largely ignore nitrates & nitrides and these are far more dangerous pollutants than the first two.
Because of the lean burn requirements on all engines, except jets for aircraft the volumes of nitrogen compounds has skyrocketed.
It is still 5/8 of SFA in total volumes which is where the stupidity lies.
Then there is embedded pollution, that which is made during the manufacture & distribution of the mower.
The difference between a 2 stroke & 4 stroke is equivalent to around 100 hours for a 160cc 2 stroke.
So the "dirty two stroke " is two years ahead of the "clean 4 stoke" before they come out of the box total pollution wise.
Most 4 stroke engines are only EPA compliant for 2 to 3 years, meaning that after 3 years their exhausts are just about the same as that of the 2 stroke which barely changes over a 10 year period.
The only test I heard of tested our 160 cc 2 stroke power torque engine against a 160 cc Honda & a 145 cc Briggs as they all claimed the same 6 hp output.
After 5 years the ( lab simulated ) use the Briggs exhaust was the same as the Victa and it rapidly got worse.
It took the Honda 8 years to get to par with the Victa, emissions wise and after that it just got dirtier.
Now when you changed the fuel il ratio from 25:1 to 50:1 the two stroke was on par with the 4 strokes from day one.
With a fuel oil ratio of 100:1 the emissions from the 2 stroke engine were actually less that the Briggs and only marginally dirtier than the Honda from new.
This study used 60 hours as a years worth of mowing and assumed that each engine would run for 10 years.
The life of a Powertorque is yet to be determined as most dating from 1982 when it was introduced are still running.

Now part of the problem has to be shouldered by ignorant boards & marketing experts.
The Victa's used to be 25:1 when we were mixing motor oil into petrol.
When marine 2 stroke oil was blended the mowers could have gone to 50:1 but boards of white men who have never mowed a lawn decided that their customers were too stupid to understand that better mixing oils would allow the engines to be run with less oil .
When ashless 2 stroke oil was blended you could safely push this out to 70:1 but the powers decided to stick with 25:1.
This caused a lot of carbon fouled engines that became hard to start and lost a lot of power so the public dumped their Victas in favour of Hondas so the board shot themselves in the foot.
When Tier II was announced the "research teams" found that with a modification to the carby cam, Diaphragm spring & main jet the mowers would run 100:1 all day and all night.

There is no arguement that a 2 stroke uses more fuel but to call them more polluting is way off beam.
If there is still petrol powered mowers in 20 years the truth about pollution from mowers will come out.
But all of the engine makers have confirmed thay can not meet the new emission regulations without going to fuel injection and then it will be touch & go.

Interesting where the requirement for high octane petrol comes from.
The Briggs, Victa , Suzuki two strokes sold here all run on plain old unleaded.
Marie two strokes did require higher octane fuel but they have not been made for near 20 years.

Over here, in Europe, octane isn't an issue, bacause all of our fuel now starts at 95. I think, in Switzerland, they still offer 92. The others abolished 92, simply so that they could reap more profits selling unneeded octane for perhaps the majority of motorists at 95 profits while maintaning one less pump. So much for that.
As far as the future of 2-cycles getting marginal because of emissions claims, you could run a clean propane or cleaner natural gas-powered 2-cycle, as long as it has pressure induction oiling. If older fuel-mix mowers can't be adapted accordingly, tough luck, unfortunately