"Nick Maclaren" wrote in message
...
In article o.uk,
Dave Liquorice wrote:
On Tue, 17 Mar 2015 08:24:27 +0000, Tim+ wrote:

Power to weight ratio probably rules out four-stroke engines for
strimmers although I'd be happy to be proved wrong.

Not to mention that 4 strokes generally have oil sumps and don't like
being operated at any angle. Two srokes with oil in fuel aren't
bothered aboout orientation which for a strimmer can be very
variable.

Something doesn't add up between "changing oil", "strimmer" and "4
stroke".

Well, there used to be 4-stroke aircraft engines, and there were
other ways of handling oil than gravity-fed sumps, but I agree
that it is unlikely. However, even strimmers may well have a
gearbox, and those generally contain oil.

It's called "dry sump", oil is held in a separate tank.
Some motor cycles have it.

There is an EUSSR directive to do away with 2T engines in favour of 4T.
To stop the oil in exhaust gases pollution.
However 4T is more expensive, heavier, more maintenence, harder to repair
etc.

So I expect they will be cheap and nasty, hence short lived.