Subject: Re: [Shop-talk] 2 stroke vs 4 stroke

From: Doug Braun <[email-masked]>
Date: Wed, 6 Mar 2013 22:41:52 -0500

I have a cheapo 10-year-old Murray lawn mower with a 4-stroke B&S engine,
that has never failed to start on the first pull, even after months of
storage. I also have a 2-stroke Ryobi trimmer that is always a pain to
start.

I suspect that any engine that is designed to operate in a fixed position
with gravity fuel feed (e.g. lawn mower) will be easier to start that an
engine that has to run when moved around (e.g. chainsaw), because of the
carb design.

Doug

On Wed, Mar 6, 2013 at 10:17 PM, Bob Nogueira <[email-masked]> wrote:

> Tonight I was curled up with the Internet looking at lawn edgers trying to
> choose one to buy.
> Based on my good experience with an Echo trimmer and Poulan chainsaw I
> found
> myself limiting my search to only 2 stroke engines.  This is countered by
> my
> experience with a Ryobi 4 stroke trimmer that was nothing but trouble.
>
>   This got me to thinking back as a kid as to how two stroke engines were
> used
> primarily in outboards,  cheap lawn mowers and chain saws, all of which had
> horrible reputations for not starting.   (model air plane engines don't
> count
> since the fuel is premixed)
>
> So to my question,  have two stroke engines improved that much over the
> years
> or did I just grow up in a town in which no one knew how to properly mix
> oil
> and gas but two stroke owners sure knew how to swear?
_______________________________________________

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Archive: http://www.team.net/archive

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From: "Karl Vacek" <[email-masked]>
Date: Wed, 6 Mar 2013 21:57:52 -0600

If you consider Echo, check the fine print in the instructions and see if it
requires 89-octane gasoline.  Bizarre requirement, but necessary for their
warrantee, at least a few years ago.  My 1970 Echo blower still runs fine on
anything, but my 2005 blower/vac/bagger died from the wrong gas before I
even knew of the requirement.

And like others have said, current 2-cycles can be a pain to start, not to
mention the stink.  4-cycles seem to fare better, though old gas is still an
issue for me.  Sta-Bil doesn't seem to help that.

Karl

-----Original Message-----
From: Bob Nogueira
Subject: [Shop-talk] 2 stroke vs 4 stroke

Tonight I was curled up with the Internet looking at lawn edgers trying to
choose one to buy.
Based on my good experience with an Echo trimmer and Poulan chainsaw I found
myself limiting my search to only 2 stroke engines.  This is countered by my
experience with a Ryobi 4 stroke trimmer that was nothing but trouble.
_______________________________________________

[email-masked]

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From: Wayne <[email-masked]>
Date: Thu, 07 Mar 2013 03:17:53 -0500

On 3/6/2013 10:17 PM, Bob Nogueira wrote:
>    This got me to thinking back as a kid as to how two stroke engines were used
> horrible reputations for not starting.   (model air plane engines don't count
> So to my question,  have two stroke engines improved that much over the years
> or did I just grow up in a town in which no one knew how to properly mix oil

I have a 2 stroke Ryobi trimmer, Echo chain saw, 70cc small Yamaha bike, 
and formerly an MTD snow blower. With basic maintenance and good fuel 
mix, and some RTFM they all start & run great. The small ones are rather 
picky about the starting procedure, esp the Ryobi, but it's right on the 
label and if followed, they start with no drama. They're lighter, 
simpler, and make more power for their size than a 4. But as ya' 
probably know, the torque & power are in a narrower, higher rpm range. 
Good for something you tend to run WOT. Don't think it would be great in 
a lawn mower.

I buy Yamaha's "Yamalube 2S" for the bike, and use it in the others, 
too. Supposedly semi-synthetic. It burns a lot cleaner than the usual 
power equipment-grade oil.

-Wayne

[email-masked]

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From: Wayne <[email-masked]>
Date: Thu, 07 Mar 2013 03:23:44 -0500

> engine that has to run when moved around (e.g. chainsaw), because of the

2-S Power Equipment, like saws or trimmers, has a "pumper carb". A 
little rubber diaphragm & check valve use engine vacuum pulses to suck 
fuel from the tank and keep the carb constantly full, and pump any 
excess back to the tank. Roll around things like mowers or bikes appear 
to use regular gravity fed float bowls.

Had to rebuild the carb' on the Ryobi last summer. Was surprisingly 
easy! (and I usually trash any carb I touch) $7 kit, clean it up, dial 
two screws and runnin' like new  :)

-Wayne

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