I don't know anything about the Troy-Built trimmers (I use a Stihl), but
there is a basic difference between 2-cycle and 4-cycle engines. The
4-cycle engine gets its oil from a sump below the pistons. This means
that the engine has to be operated within a few degrees of some
orientation in order to get proper lubrication. If you turn the engine
upside down or sideways you compromise the lubrication and shorten the
life of the engine. Short excursions will probably not hurt it, but
extensive operation at odd orientations will not do it any good.

The 2-cycle engines get their oil through the fuel, so as long as the
fuel is going into the engine, they will be lubricated. If the fuel
stops going into the engine they will stop and lubrication will not be
required. The carburetor in trimmers is designed to operate at many
different orientations (as long as the fuel can get into it). This means
you can use your trimmer in the "normal" orientation, i.e. to trim the
grass at foot level, or you can use it to trim shrubs above your head or
even the ceiling of an arbor.

If you are never going to use your trimmer on anything but grass at foot
level, the 4-cycle engine would be recommended because they are
(generally) cleaner than the 2-cycle engine. The oil going through the
2-cycle engine comes out mostly unburned, and so contributes to air
pollution. However, you should never say never, so you (or someone you
loan it to) will probably use your trimmer on something else eventually.
If you understand the engine requirements for oil and only operate the
engine in the "other way" for a few seconds at a time, you should be
able to use the 4-cycle engine. Make that clear if you loan it out.




John McDougald wrote:
OK, finally got permission from the wife to buy a new gas trimmer. I am
looking at the Troy Built models and was wondering what the difference is
between the 4 cycle and 2 cycle types other than the gas/oil mixture factor.
Is there any significant increase in power between the two types? Which one
is better power wise, the 2cycle has a 31cc engine and the 4cycle has a 26cc
engine. Is there any advantage of one over the other?
Thanks for the input. I really just want to get the best item for the
money.

John T McD.