Our strimmer is pumping out oil from the breather pipe has anyone got any idea what is causing this. the oil has been changed and the level is correct.

On 16/03/2015 16:00, plotholder wrote:
Our strimmer is pumping out oil from the breather pipe has anyone got
any idea what is causing this. the oil has been changed and the level is
correct.

I've cross-posted this to uk.d-i-y - people there will know.

I'd suspect piston rings, but ICBW. Is the compression OK? Does it
smoke when running? Is it using oil?

Andy

"Vir Campestris" wrote in message
o.uk...
On 16/03/2015 16:00, plotholder wrote:
Our strimmer is pumping out oil from the breather pipe has anyone got
any idea what is causing this. the oil has been changed and the level is
correct.

I've cross-posted this to uk.d-i-y - people there will know.

I'd suspect piston rings, but ICBW. Is the compression OK? Does it smoke
when running? Is it using oil?

It's caused by combustion gasas getting into the crankcase.
Worn piston/piston rings/cylinder bore.
Or worn valve guides.

Caused by poor design/cheap and nasty/no oil/faulty oil pump/extreme old
age.

You may well find repair uneconomic.
Benefits of having 4T engine instead of 2T (anti-pollution measure).

"harryagain" wrote:
"Vir Campestris" wrote in message
o.uk...
On 16/03/2015 16:00, plotholder wrote:
Our strimmer is pumping out oil from the breather pipe has anyone got
any idea what is causing this. the oil has been changed and the level is
correct.

I've cross-posted this to uk.d-i-y - people there will know.

I'd suspect piston rings, but ICBW. Is the compression OK? Does it smoke
when running? Is it using oil?

It's caused by combustion gasas getting into the crankcase.
Worn piston/piston rings/cylinder bore.
Or worn valve guides.

Caused by poor design/cheap and nasty/no oil/faulty oil pump/extreme old
age.

You may well find repair uneconomic.
Benefits of having 4T engine instead of 2T (anti-pollution measure).

Where would these valve guides be in a two-stroke engine? Power to weight
ratio probably rules out four-stroke engines for strimmers although I'd be
happy to be proved wrong.

Tim

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".

--
Cheers
Dave.

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.


Regards,
Nick Maclaren.

"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.

In uk.d-i-y Tim+ wrote:

You may well find repair uneconomic.
Benefits of having 4T engine instead of 2T (anti-pollution measure).

Where would these valve guides be in a two-stroke engine? Power to weight
ratio probably rules out four-stroke engines for strimmers although I'd be
happy to be proved wrong.

I have a relatively cheap Ryobi 4 stroke strimmer, same weight as the
2 stroke it replaced and *much* better in many ways. In particular
it's dead asy to start whether cold, warm or hot. The only complaint
I have is that the 'dipstick' really isn't very clever.

--
Chris Green
·

On Tue, 17 Mar 2015 08:42:29 +0000 (GMT) Dave Liquorice wrote :
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".

That was always my understanding: four strokes on things like mowers that
operate at defined angles and two strokes for strimmers etc. But there's a
thread on Renovate forum that suggests that things have moved on

http://www.renovateforum.com/f216/wh...stroke-115351/

--
Tony Bryer, Greentram: 'Software to build on',
Melbourne, Australia www.greentram.com

On 17/03/2015 08:24, Tim+ wrote:

Where would these valve guides be in a two-stroke engine? Power to weight
ratio probably rules out four-stroke engines for strimmers although I'd be
happy to be proved wrong.

Honda are four-stroke, and pretty good.

On 17/03/15 08:24, Tim+ wrote:
Power to weight
ratio probably rules out four-stroke engines for strimmers although I'd be
happy to be proved wrong.


https://www.youtube.com/watch?v=NZZ3HoZAnUg

Very tempting - but I haven't looked for a price yet.

--
Kevin

"Tim+" wrote

"harryagain" wrote:
"Vir Campestris" wrote
, plotholder wrote:
Our strimmer is pumping out oil from the breather pipe has anyone got
any idea what is causing this. the oil has been changed and the level
is
correct.

I've cross-posted this to uk.d-i-y - people there will know.

I'd suspect piston rings, but ICBW. Is the compression OK? Does it
smoke
when running? Is it using oil?

It's caused by combustion gasas getting into the crankcase.
Worn piston/piston rings/cylinder bore.
Or worn valve guides.

Caused by poor design/cheap and nasty/no oil/faulty oil pump/extreme old
age.

You may well find repair uneconomic.
Benefits of having 4T engine instead of 2T (anti-pollution measure).

Where would these valve guides be in a two-stroke engine? Power to weight
ratio probably rules out four-stroke engines for strimmers although I'd be
happy to be proved wrong.


Yes Honda do use 4 stroke engines in their strimmers and brushcutters

http://powerequipment.honda.com/trimmers

and they say they can be used 360°, even upside down.

Friend has one because it is so quiet and with little vibration.
--
Regards. Bob Hobden.
Posted to this Newsgroup from the W of London, UK

On Tue, 17 Mar 2015 10:00:47 +0000, wrote:

In uk.d-i-y Tim+ wrote:

You may well find repair uneconomic.
Benefits of having 4T engine instead of 2T (anti-pollution measure).

Where would these valve guides be in a two-stroke engine? Power to weight
ratio probably rules out four-stroke engines for strimmers although I'd be
happy to be proved wrong.

I have a relatively cheap Ryobi 4 stroke strimmer, same weight as the
2 stroke it replaced and *much* better in many ways. In particular
it's dead asy to start whether cold, warm or hot. The only complaint
I have is that the 'dipstick' really isn't very clever.

You're not telling us anything new here, most 'Dipsticks' aren't
very clever, hence its use as a derogatory name for stupid people.
--
J B Good

"plotholder" wrote


Our strimmer is pumping out oil from the breather pipe has anyone got
any idea what is causing this. the oil has been changed and the level is
correct.

That is usually caused by overfilling the oil but then you would also get
smoke from the exhaust.
Or damage inside the engine ... badly worn bores but that starts little and
builds up over time/use, or damaged/broken piston rings or valve seals gone
but with all those you also usually get smoke from exhaust too. Strange that
it was not around until you did an oil change?

--
Regards. Bob Hobden.
Posted to this Newsgroup from the W of London, UK