Are 2-cycle engines or 4 cylce engines 'better'?

[dean (archive)]

Because I've been tempted to buy some of the new Honda 4 cylcle engine-powers garden equipment, and until recently the really small engines have always been 2 cycle. Or at least I think they have.

Dean

 

[Kyle Boatright]

Because I've been tempted to buy some of the new Honda 4 cylcle engine-powers garden equipment, and until recently the really small engines have always been 2 cycle. Or at least I think they have.

Dean

Two stroke engines are lighter for the same power output. They are also usually noisier, shorter lived, use more fuel, and pollute more.

Choose the best compromise for the job.

KB

 

[Rolling Thunder]

Because I've been tempted to buy some of the new Honda 4 cylcle engine-powers garden equipment, and until recently the really small engines have always been 2 cycle. Or at least I think they have.

Dean

Use two cycle for equipment that needs to be tilted, such as:
chain saw, trimmer, etc.

Use four cycle for tools that are always used level on wheels, like:
lawn mower, edger, etc.

Thunder

 

[BocesLib]

This really depends on the type of equipment you want to buy. I have honda engines on my pressure washer, generator and snowblower (all 4 cycle). Craftman 4 cycle edger and 4 cycle backup lawnmower.

My 2 cycle equipement consists of my lawnboy, echo weed wacker, mccullen chainsaw and old backup snowblower.

The 2 cycle stuff is great with it being light weight and can really go in any direction without the motor not being lubricated.

The 4 cycle really has the power though anything and really sips fuel.

In terms of maintence, 2 cycle is easier. The 4 cycle you need to change the oil every year. But its rather easy to do anyway. Over the long haul, I really go like honda engines. They beat the heck out of briggs and tucemsen engine.

 

[Chris Lewis]

Except for Old LAwnboys

Except if you need parts. I was visiting a Lawnboy dealer today, and he said that now that Toro has bought them, and now that most places are banning 2 stroke lawnmowers, parts for old units will be virtually impossible to obtain, unless you're lucky and the dealer already has it in stock.

With Homelite, the situation is worse. John Deere has
bought 'em. You can't get Homelite parts from Deere dealers, and the Homelite dealers can't (or soon won't be able to)
get parts either.

Fortunately, the dealer had my homelite gaskets in stock.

 

[BocesLib]

Actually my snowblower is the only one that uses a residental grade motor (gc160) its a honda hs520as.

The generator and power washer use the gx160 engines.
(I also have a gx110 and gx120 sitting there too for future use)

The gx commercial engines are tuff to kill. They should last the regular home owner years if properly taken care of.

Tom

 

[Jim (archive)]

Many of the cheaper ones are shorter lived, but it is not really part of being 2 cycle. Remember when Saab had a life time warrantee on their 2 cycle automotive engines? It is a great way to lube the engine, but it can also be just part of a cheap way of building an engine.

Amazing how quick their 850cc Monte Carlo GT was.

 

[TPutmann]

You cant even GIVE me a 2 cycle engine for FREE. I have hated every one of them that I have ever owned, and I end up fixing the damn things more than using them. I am referring to the small ones like chainsaws, weed whackers, etc. I threw all of them in the trash and bought electric ones. If you want to spend half your weekend pulling the damn strings on the tool, get a 2 cycle, but you'll also be spending up to half the cost of a new tool each year to get the damn thing fixed about 5 times each year. No 2 cycle tool will ever be allowed on my property again.

Seeing what everyone said on here about Lawn Boy 2 cycle mowers, I also tend to disagree. I bought one at a garage sale.. It worked for awhile, but like the chainsaws, it needed to be pulled and pulled and pulled to get it to start. I drained the gas in fall. The next spring I pulled that cord for hours, added carb cleaner, changed the plug and air filter and yanked on that cord for a few more hours. By that time, I went and got my trusty over 20 year old 4 cycle 3.5HP Briggs engine mower that is so worn I have to add oil everytime I mow because it smokes like crazy. I had not used it in about 2 years, and forgot to drain the gas. I gave the string one pull and it was running. The Lawn Boy went in the trash, I bought another newer 4 cycle mower, and still got that old junker that always starts, just in case I need a spare.

 

[Art Todesco]

Some personal ramblings about 2 cycle vs. 4 cycle
tools:
I have a 2 cycle leaf blower, weed whacker & snow
blower; 4 cycle mower, power washer
and generator. The 2 cycle engines are somewhat
harder to start, however, the
4 cycle power washer w/3.5HP B&S is the worst at
starting. It says easy "easy
start design." Right! I almost always have to
use starting fluid on this one when the
engine is real cold. One problem I've noticed is
the priming bulb. They usually
say to press 3 times max! Well, if engine has the
gas tank under the carb, I press
it many, many times until I hear and feel the gas
moving (leaf blower, weed whacker,
power washer). If the gas tank is above the carb,
2 or 3 presses is fine. Also, I
have noticed that every engine want to be started
in its own way, i.e. chock position,
throttle, etc. I have also noticed on the 2 cycle
engines, ambient temperature seems to
play a big part. I have to adjust the air/gas
mixture when the weather is really hot.
The one real objection that I have with 2 cycle
engines is that I come in the house
after using the tool and I smell like gas and oil.
This doesn't seem to happen with
the 4 cycle tools. Some of that might be that the
leaf blower and whacker are much
closer to your body than say a mower. But it also
occurs when using the 2 cycle
snow blower which obviously is pushed like a lawn
mower.

 

[barry (archive)]

Betcha didn't know that EMD (GM locomotive) diesel engines are 2-stroke. Besides whole series of Detroit Diesels. Back when, it was their way of upping power/weight.

Same reason for consumer 2-strokes: power/weight. In addition to not having to keep crankcase down to avoid creating smokescreen.

You'd do best to invest in quality tool, that works for you. With engine type choice only influenced by quality and whether it requires you to keep more types of fuel mix on hand. (Kids running 2-stroke on pure gas are a problem, too.)

HTH,
John

 

[Stormin Mormon]

Years ago, I learned that two stroke engines have more HP per pound of engine weight. Cause the piston fires on every stroke. Four cycles have an exhaust stroke, which means that the cylinder fires every second time. I believe the spark plug sparks every time the cylinder comes up. But, during the exhaust stroke, the spark is wasted.

Many or most of the lawn mowers I've worked on (almost all four stroke) the oil has been low.

 

[Kevin Ricks]

Because I've been tempted to buy some of the new Honda 4 cylcle engine-powers garden equipment, and until recently the really small engines have always been 2 cycle. Or at least I think they have.

Dean

Just bought a 4 cycle Troy-Bilt string trimmer and I am happy with it so far. Here are some things I have found. It weighs about 1 pound more than the 2 cycle model (as stated in brochure). The 4 cyc units cost about $60 more than similar 2 cycle models. The 4 seems to vibrate a bit more, but not too bad. It seems quieter than the 2, but I still wear ear plugs. After using the 4, my hair & cloths don't smell like burnt oil gas mix. My owners manual states that a valve clearance adjustment must be done every so often. 10 hrs 1st time - 25 hours after that. Same for oil changes.

I went to the 4 because I was tired of having to mix oil/gas. I have 3 different things with 2 cyc engines, and all 3 required different mix ratio.

Kevin

 

[Edwin Pawlowski]

Yeah, 2 cycles suck bigtime! I've read that 2-cycle motors are banned in certain areas in California - makes sense to me, they have twice the exhaust stoke of 4-cycle so there is definitely an air pollution issue here.

Your conclusion is correct, but the reasons are wrong. The number of strokes does not determine how much pollution is emitted. Displacement, quantity of fuel, content of oil are more important.

 

[Duane Bozarth]

Not to mention that you are mixing incoming air/fuel with exhaust in each stroke, resulting in poor combustion... I wonder if a high ethanol fuel would be cleaner for a 2 stroke?

What do 2-stroke mfr's say about >E10 and oil mixtures?

Superficially, I'd think lubrication would be even more difficult.