Banning two-stroke lawn equipment

[Trials]

How about the same way as a four stroke?
... which is usually not a "wet sump".
A lawn mower with no oil pump has a "wet sump". In a "wet sump" motor the crank/big end dips into the oil reservoir, splashing oil around.
Terribly in-efficient.
Cars and bikes have a modified or semi dry sump, with the oil reservoir at the bottom of the motor, that way you only need one oil pump.
In a true dry sump, you need a scavenge oil pump, to pick up the oil and pump it to the reservoir, and a pressure pump that delivers oil, under pressure, from the reservoir to the motor

I am probably the biggest fan of two strokes here BUT the two strokes found on lawn care equipment, that is built and designed to be the lowest price possible, are the most polluting motors out there and are no comparison to bike or sled motors, that have stringent EPA legislation... even for off road vehicles.

You can't put oil in the sump of a 2-stroke, the fuel and air has to travel through the crankcase.

The piston is literally surrounded on all sides by air and fuel at about a 15:1 ratio.
You're going to need to come up with materials that are extremely thermal stable and require no lubrication, or she's gonna need to burn oil.

 

[Trials]

I think the bigger issue for pollution is the unburned fuel related to port timing, conventional 2strokes need an overlap of 120 degrees when both ports are open to mix fuel/air so unburned gas houses thru the exhaust. The new designs are direct injection, the exhaust valve is closed before fuel is injected.

Modern 2 strokes are also more efficient on fuel and oil. Modern lubricants also burn more completely than stuff we used decades back. Love to see them come back.

100:1

"The new designs are direct injection, the exhaust valve is closed before fuel is injected." Then where does the air come from?
It still needs to scavenge no matter how late you leave adding the fuel or you have no compression and continuous exchange of burnt and unburnt gases.

Pretty hard to clean up the exhaust emissions too, because you can't put a catalytic converter on a 2-smoke even with only 100:1 oil ratios.

Lots of 2-stroke competition trials bikes still around, except in California park lands.
The direct injection on the 2-stroke works but has issues, like to start with Ossa did that and it required a battery.
... and trust me they smoke lots.

 

[TK4]

see: Transfer Port injection

2020 KTM 300 XC TPI First Ride Review

We raced the 2020 KTM 300 XC TPI at round 7 of the World Off-Road Championship Series (WORCS) at Grays Harbor ORV in McCleary, Washington.

www.dirtrider.com

 

[Scuba Steve]

100:1

"The new designs are direct injection, the exhaust valve is closed before fuel is injected." Then where does the air come from?
It still needs to scavenge no matter how late you leave adding the fuel or you have no compression and continuous exchange of burnt and unburnt gases.

Pretty hard to clean up the exhaust emissions too, because you can't put a catalytic converter on a 2-smoke even with only 100:1 oil ratios.

Lots of 2-stroke competition trials bikes still around, except in California park lands.
The direct injection on the 2-stroke works but has issues, like to start with Ossa did that and it required a battery.
... and trust me they smoke lots.

2 stroke engines that have wet sumps have been around for a 100 years look up a 2 stroke diesel.

Sent from my moto g(8) plus using Tapatalk

 

[Trials]

Let me know when you get all the 2-stroke bugs worked out so you don't need to burn oil with your ethanol blend.

 

[J_F]

intake air on a 2 stroke diesel does not end up in the crankcase
enters through the ports after power stroke
exhaust exits through overhead valves prior to compression

they don't rely on movement of the piston and atmospheric pressure to move air
they use a gear driven blower

fuel is direct injection

 

[Trials]

This is starting to sound like a very complex 2-stroke engine if we're going to need to put fuel injectors and air compressors on it as well as oil feed and returns through a connecting rod, plus possibly poppet valves? unless this is not going to be a reciprocating engine,
and you still need that piston and cylinder that does not require lubrication for that KTM.

I think the conventional 4-stroke Honda is going to whoop you on production costs and it only needs to fire on every other stroke which ultimately provides better fuel economy

... you have to remember one of the most endearing features of a conventional 2-stroke is simple and cheap to build.

 

[J_F]

patent filed by Kawasaki not long ago for a 2 stroke
it was supercharged so not relying on piston timing for scavenge
direct fuel injection and assuming overhead servo controlled valves

part of a hybrid drive train
no idea if they've built the engine yet

 

[Trials]

Kawasaki Patents Supercharged Two-Stroke Inline-Four Engine | DriveMag Riders

Kawasaki seems to be working on a new supercharged engine according to these patents from Cycle World and MotoIT. The company aims to increase fuel efficiency

riders.drivemag.com

Sure looks like every part you would need to build a 4-stroke engine except they apparently want to make it fire on every stroke. Can't see where that is going to save fuel but go for it, I suspect a hit and miss engine would use a lot less fuel.
and btw it's to power an electric motor, it's a tiny gasoline generator.

... zero chance of this Kawasaki super 2-stroke tech finding its way into a chainsaw lawnmower or weed whip, they made it more complex heavy and expensive to build then a 4 -stroke.

 

[Brian P]

A two-stroke engine, by the time you're done dealing with the emissions headaches and the lubrication headaches, will end up more costly than a four-stroke AND still not capable of reaching the same emission levels.

Detroit Diesel two-strokes for decades used a Roots "supercharger" (scavenging blower) to blow air through intake ports in the cylinder and they used cam-driven exhaust valves in the head. They kept them in production for a while by using electronic injection controls, but eventually gave up when faced with 1990s-era heavy-duty-vehicle emission standards, and those are a lot more stringent today.

The various Bombardier/Rotax/Aprilia etc gasoline-direct-injection two-strokes still use crankcase-scavenging, but there's a tiny oil pump feeding a tiny bit of oil to the rolling-element bearings in the crankshaft, and that splashes onto the cylinder walls. They're a lot more efficient than the old premixed-air-and-fuel (carbureted, or throttle-body-injected) two-strokes, but they still have emissions problems because of the inherent oil consumption. And the direct injection system adds cost.

Meeting emission standards with four-strokes is known, proven, reasonably robust technology. My cbr125 has closed-loop EFI with a 3-way catalyst. The lambda sensor is screwed into the cylinder head, right at the exhaust port. Standards become more stringent? -> catalyst becomes bigger (more-or-less) and the electronics get faster and more accurate.

 

[nobbie48]

one of the Euro bike makers, not sure but maybe KTM, memory is failing me
is developing a clean 2 stroke

direct fuel injection and closed loop - dry sump crankcase lubrication
no oil in the gas or in the combustion chamber

yeah those blowers are not necessary, certainly for a city sized lot
I replaced my gas powered one with electric

had a Dewalt 20V kit and a few cordless tools with it
added the blower - same batteries and charger
works just as well as the gas one and much quieter

I have a 40 volt mower and blower. The mower does about 2,000 square feet of lawn with a bit of battery charge left for the trimmer. The 40 volt blower is OK but won't blast the maple keys out of the grass.

I had a landscaper use his Stihl gas blower to go over the approximately 800 SF and they blew out over a half bushel of keys. Yes very noisy but needed. I'm considering an electric snow blower to replace the clatterbox 4 stroke. Not every tool has to make noise.

As pointed out cost is a big factor. We all want clean and quiet but cheap comes first. A 40 volt blower package is probably half the cost of a Stihl. Would a $800 electric blower work as well as the Stihl?

Part 2. For the first time in years I pulled out a corded drill and it worked fine. When a battery dies where do the chemicals go?

We burned hydrocarbons for centuries before we saw where they were accumulating.

Different strokes for different people.

 

[GreyGhost]

I have a 40 volt mower and blower. The mower does about 2,000 square feet of lawn with a bit of battery charge left for the trimmer. The 40 volt blower is OK but won't blast the maple keys out of the grass.

I had a landscaper use his Stihl gas blower to go over the approximately 800 SF and they blew out over a half bushel of keys. Yes very noisy but needed. I'm considering an electric snow blower to replace the clatterbox 4 stroke. Not every tool has to make noise.

As pointed out cost is a big factor. We all want clean and quiet but cheap comes first. A 40 volt blower package is probably half the cost of a Stihl. Would a $800 electric blower work as well as the Stihl?

Part 2. For the first time in years I pulled out a corded drill and it worked fine. When a battery dies where do the chemicals go?

We burned hydrocarbons for centuries before we saw where they were accumulating.

Different strokes for different people.

A previous neighbour had an electric snow blower. It wasnt quieter. Price point engineering means it had a universal motor and sounded like a skil saw running constantly. Horrible grating noise.

 

[nobbie48]

A previous neighbour had an electric snow blower. It wasnt quieter. Price point engineering means it had a universal motor and sounded like a skil saw running constantly. Horrible grating noise.

Point taken.

I was thinking of a 40 volt battery Ryobi since we have the battery and charger. I'll check into sound levels. The driveway isn't that large but sometimes the city plow leaves a drift across the end.

TBH it isn't worth getting the blower out of the shed and to the front unless there's 3-4 inches of snow. The city does the sidewalk and I'm in no rush so a bit of shoveling isn't a bad thing.

 

[Delboy]

California banned 2-stroke motorcycles from operating in their federal parks a long time ago.

Basically they don't want you to run a motor that constantly burns oil as part of its normal operation, with the logic being fairly obvious :/ you are putting those hydrocarbon emissions directly into the atmosphere.

I'm not sure that's correct.

I have a 2004 KX125 which is red stickered so I can't ride it on about 20% of state lands in the summer. Fall, winter and spring are OK. The other 80% of lands are fine all year. Its due to air basin data and fire restrictions (although I'm not sure how many more sparks a 2 stroke spits out compared to a 4 stroke)

What they did do is ban the sale of two stroke based off-highway motorcycles starting with the 2022 model year. The exception is 110cc and under so most kids bikes will be exempt. The red sticker program is extended through 2025 and after that all motorcycles will be treated the same.

Or course bikes bought before 2022 are exempt as they are grandfathered and you can still ride them, but it still doesn't stop someone from driving to Nevada and buying a new YZ125 in 2022.

Its the same as the thought process they put behind the ban on semi automatic weapons. You can just drive to Nevada and buy 100 AK47's if you want. I'm not actually sure what it achieved except that the Governor had a talking point on his resume.

Its also strange that under California law, direct injection two-stroke engines for watercraft are considered clean emission engines and thus you get a green sticker that can be used on every water body in California. I wonder if someone produced a direct injection 2 stroke bike would it also be considered green?

Its all beyond my pay grade.

 

[Trials]

I'm not sure that's correct.
...

First I heard about it was when they were wanting to host a world round trial in California and they ended up having it at Donner Ski Ranch, which is obviously not inside a state or national park. I think that was about 19 years ago.

"direct injection 2 stroke bike" Ossa had that, the bikes were green, but not in the ecology sense, they blow blue smoke in your eyes when you're behind one just the same as the Beta, TRS, GasGas, Sherco, Yamaha's etc.

 

[Mad Mike]

Fuel Injection - as cheap as a carb these days, easier to tune, more dependable..

Kawasaki Patents Supercharged Two-Stroke Inline-Four Engine | DriveMag Riders

Kawasaki seems to be working on a new supercharged engine according to these patents from Cycle World and MotoIT. The company aims to increase fuel efficiency

riders.drivemag.com

Sure looks like every part you would need to build a 4-stroke engine except they apparently want to make it fire on every stroke. Can't see where that is going to save fuel but go for it, I suspect a hit and miss engine would use a lot less fuel.
and btw it's to power an electric motor, it's a tiny gasoline generator.

... zero chance of this Kawasaki super 2-stroke tech finding its way into a chainsaw lawnmower or weed whip, they made it more complex heavy and expensive to build then a 4 -stroke.

If you can eliminate the120 degree overlap in port openings, a 2 stroke is more fuel efficient than a 4 stroke - new designs do that. Eliminating the mechanical drag is also a big fuel saver -- 2 strokes have 50-75% less mechanical drag.

First I heard about it was when they were wanting to host a world round trial in California and they ended up having it at Donner Ski Ranch, which is obviously not inside a state or national park. I think that was about 19 years ago.

"direct injection 2 stroke bike" Ossa had that, the bikes were green, but not in the ecology sense, they blow blue smoke in your eyes when you're behind one just the same as the Beta, TRS, GasGas, Sherco, Yamaha's etc.

I think the modern 2 strokes are not supposed to be run with synthetic oil. My 2 strokes smokes like the Marlboro man on synthetic.

 

[Trials]

If you're not running full synthetic 2-stroke oil at 80 or 100 to 1 then you'd be running something else at about 35 to 1
Either way unburnt oil is going to slowly collect in you muffler packing until it eventually catches fire or plugs up your exhaust.

You'll frequently see a 2-stroke trials rider come to a full stop and totally pin the throttle before going up a big rock or hill, just to clear out the engine a bit. I never need to do that with my 4-stroke, I just pin it all the way up the hill (fuel injected). Header pipe on the 4-stroke runs way hotter, you end up burning your riding pants even more then the 2-strokes. ymmv.

 

[Brian P]

Any engine design that uses piston-porting is going to have oil-consumption and related emissions headaches. The piston rings have to cross the ports. The piston rings have to be lubricated. Some of the oil used to lubricate the rings is going to either escape out the exhaust ports or get into the intake air stream and go through the combustion cycle (imperfectly). The latter situation is arguably better because at least the oil is given a fighting chance at being burned in the engine cycle. Detroit Diesels used ported intake and exhaust valves in the head. Still couldn't meet 1990s-era emission standards.

Kawasaki's design avoids piston-porting ... but it is every bit as complex as a 4-stroke engine AND it is very subject to intake air short-circuiting out the exhaust and therefore has to use direct fuel injection AND it's reliant on forced-induction. There are some combustion-related headaches that I can foresee with this design (How do you operate the engine at low load? Lean air/fuel ratio is hard to ignite. High exhaust residual is hard to ignite. Compression-ignition? If so ... cold starting?) and some emissions-related headaches (catalysts require a chemically-correct air-fuel ratio; scavenge air short-circuiting out the exhaust would have to be offset by rich in-cylinder conditions and that's atrocious for efficiency).

The (throttled and/or variable-valve-timed), stoichiometric-operation, spark-ignition, 4-stroke engine will be with us until the end of the internal combustion engine when it all gets replaced by batteries and electric motors ...

 

[Zoodles95]

This is interesting timing... I bought a battery powered snowblower tonight and I was going to start a thread about battery powered home outdoor equipment and get some feedback. Then I saw this thread and I thought I would post my impressions about 80V ownership.



This is my second 80V Greenworks device. So, this 4 A/hr battery is identical to the one for our lawnmower we picked up in the spring. Same good quality charger too.



Got it all assembled and now it is ready to go when needed. The lawnmower has one season under its belt and it has been awesome.




The lawnmower is self propelled via RWD. I looked at gas but with my wife's M.S. she was uncomfortable with the weight and having to start it. She called the Greenworks "The Tesla" and although I am supposed to be doing all the yard work she likes to do the lawn on a temperate day and the self propulsion literally pulls her up the hill. In short we have been very happy with this lawnmower and hence why we decided to go the battery route for the new snowblower. The battery can do our large front yard with some reserve left over. Quick charger can charge the battery to full in under an hour. The only time the lawnmower got taxed was when we did our neighbor's yard after her husband died. It was very long so it taxed the battery. I had to charge it to finish it off. When you lawn does not look like a field of wheat there is enough juice there to do a large 68ft wide yard.

This is where the battery goes in the lawnmower:


Now that we have a second device we now have 2 identical batteries and chargers. Now any "range anxiety" I may have had is gone.


In the snowblower there is a spot for a spare battery. So, if I were to run out of power I could easily swap the batteries and get back to work. I have no idea how much run time I am going to have with a fully charged battery. At our old house I'm sure that one battery would have done the job easily. The new digs have a decent sized driveway and walkway so potentially I may well need the second battery to get it done in one sweep. Will see...


We had a corded electric snowblower that worked great but it was a pain with the cord getting stuck and unplugging etc. What I found with the 80V lawnmower is that it had comparable power to the best electric lawnmowers I have used with the low maintenance and ease of use of electric with the freedom of gas in not having a cord. Now we will have the same cord freedom with this new snowblower. 80V is close to gas powered and that is where I would recommend to anyone looking at jumping into this. Lots of reviews out there of 40V units and choppy lawn cutting etc. 40V can work but it is a whole level below 80V. At 80V it is getting very close to a plug in or smaller cc gas engine. There are a few 120V cordless systems out there but that is fairly new tech; greenworks does not have a 120V system themselves yet. 120V though is the ultimate having your cake and eating it too.

Just the same our 80V units have a lot of steel in their construction and unlike our old electric. plug in Toro, snowblower which had plastic impellor etc the Greenworks is a steel shaft "slaps/scoops" with heavy rubber which will flex and are replaceable. A much higher quality and "beefy" unit than my old plug in stuff. Again, bridging the gap between electric and gas.

I guess the advantage of this stuff other than not having to store gas, use fuel stabilizer etc, is that the power comes from a central power souce (the grid) versus hundreds of thousands or millions of 2 stroke motors in various state of repair and emissions.

Once 120V systems with 6A/hr or better batteries are mainstream then there will be little to no advantage for an average person to stay with gas.

I still have some corded stuff. The lawn trimmer is corded and I am on the fence about upgrading it to a cordless one. I bought a Greenworks hedge trimmer this year and went corded because we typically target an area or bush that needs trimming. It is not like I go all over the place like the lawnmower so we saved money by going corded.


At some point I need a leafblower and the debate will come up again: corded or cordless. Hmm...

So, sorry for the usual rambling, long winded Zoodles post. Anyone else own cordless lawn equipment and want to chime in on their experiences?

 

[Brian P]

No experience but that's a great idea to have a battery-compatible lawnmower and snowblower. I have a cord-connected electric lawnmower that is about 15 years old (pre-dating availability of decent battery-powered equipment) and that cord is indeed a royal pain in the tail. There's one spot in the side yard that I can't reach without doubling-up extension cords. (Neighbor does it in trade for me doing their piece of the front yard) How's the lawnmower do in heavy grass? (back lawn tends to get neglected too long ... no doubt part of the neglect is because the cord is a hassle)