Garden power equipment 2-Stroke v.s. 4 Stroke

WVBill · May 30, 2009

Been reading the thread on chainsaws on a stick. Good discussion and info on manufacturer comparisons but I've been seeing that manufacturers offer both 2-Stroke and 4-Stroke engines.

I've only ever had 2-stroke engines on my small garden power equipment. so now I have that choice...

Recommendations - pro's/con's of each.??

jdbower · May 30, 2009

When I moved from a small property to a larger one I wanted to keep things simple and make everything regular gas powered. I got a 4-stroke snowthrower, a 4-stroke trimmer, and then a diesel tractor. Oops. Two gas cans isn't bad and the diesel is just for transport anyway. Then came the need for a chainsaw, and I haven't seen any 4-stroke models so I ended up with a third gas can for a gas+oil mix. The best laid plans and all...

In general (always compare stats over technology!) 4-stroke is heavier for an equivalent power, I think they have more torque (much like a 25HP diesel will have more torque than a 25HP 4-stroke), and I find them easier to start. 2-stroke on the other hand tends to operate at higher RPMs so they're a bit better suited for some applications like chainsaws (where the weight is also a big factor) and trimmers. Still, my 4-stroke Toro trimmer works just fine and it doesn't smoke at all compared to a 2-stroke engine. I think it's quieter than a comparable 2-stroke as well, but I still use ear protection so that's like saying having an airport next door that services 737s instead of 747s is quieter... I'd say the 4-strokes seem like less maintenance, but the amount of cleaning one needs to do to a chainsaw is very different than what one needs to do to a trimmer.

Another option that's getting a bit better are cordless electrics. On a whim when my Husqvarna wouldn't start one day I got a Black and Decker 18V chainsaw. While it's hardly the only chainsaw you'll ever need it's fantastically easy for light work up to 6-8" cuts - the problem is remembering it's not a toy and can actually do serious damage! The 18V hedge trimmer is also a nice way to add another battery (two is a necessity, keep one charging while you use the otehr), and they have a string trimmer that I'd consider if I needed to invest in repairs for the Toro - worst case I'll end up with a third battery if it doesn't work well. Undoubtedly they're not for every property or use and while the torque is great the speed is a bit lacking, but being very quiet and almost no maintenance is a huge plus.

jinman · Jun 1, 2009

For those of you with 4-stroke string trimmers and such, how is the crankcase oil handled on a 4-stroke that gets rotated to all positions? A 2-stroke doesn't matter because it pulls the fuel-oil mix through the crankcase. I've just never taken the time to research how the 4-stroke works.

Dmace · Jun 1, 2009

jinman said:
For those of you with 4-stroke string trimmers and such, how is the crankcase oil handled on a 4-stroke that gets rotated to all positions? A 2-stroke doesn't matter because it pulls the fuel-oil mix through the crankcase. I've just never taken the time to research how the 4-stroke works.

I believe they use a dry sump system: Dry Sump

Instead of having the oil sit in a large pan (where the oil can slosh around) and get picked up by the spinning crankshaft and pick up, the oil stays in another tank mounted anywhere and the oil is pumped into the engine via an oil pump and then pumped back into the tank.

If I were looking for a new trimmer, it would be 4-stroke. Longer lasting and no oil mixing (less gas cans in shed) and quieter. My 2-stroke trimmer is very loud and only 2 years old. The 2-stroke is easier to rebuild but I doubt the trimmer body will outlast the 4-stroke engine.

jdbower · Jun 1, 2009

jdbower said:
...my 4-stroke Toro trimmer...

Whoever wrote this must be hallucinating! Toro doesn't make a 4-stroke trimmer to my knowledge, perhaps I - er - *he* meant Troy-Bilt. What can I say, they're both red and it's the color that matters!

turbo36 · Jun 1, 2009

Not sure how others do it but Sthil does not have an oil sump, they continue to use a 50 to 1 mix.

STIHL Power tools

Dmace · Jun 1, 2009

turbo36 said:
Not sure how others do it but Sthil does not have an oil sump, they continue to use a 50 to 1 mix.

STIHL Power tools

It will be nice to see what kind of life they get out of those engines but the main reason for getting a 4-stroke over a 2-stroke engine is it does not burn oil. This 4-stroke still requires pre-mix gas and burns the oil just like a 2-stroke, what's the point...?

RobertN · Jun 1, 2009

jinman said:
For those of you with 4-stroke string trimmers and such, how is the crankcase oil handled on a 4-stroke that gets rotated to all positions? A 2-stroke doesn't matter because it pulls the fuel-oil mix through the crankcase. I've just never taken the time to research how the 4-stroke works.

I'm not sure... I have a 31cc Honda trimmer, the one with the big handle bars and shoulder harness. It only uses like 3/4 cup of oil. I think... that is just has enough oil in the crankcase that it gets slung all over. I don't know how any get on the valvetrain.

It is much quieter than my older Husky 225R brush/trimmer. It has a different power band too. I think the 31cc 4-stroke works about the same as the 25cc 2-stroke.

I do really like the 4-stroke. It's a little heavy, but not bad.