My chainsaw always used to be very easy to start... turn it over with a
couple of pulls, then ignition on, choke out, throttle in starting
position and off it would go first or second pull.

Now I had it serviced last year, and it was "ok" after that, but not
quite as easy to start. Went to use it this year, and could not get a
peep out of it. Gave up, and tried a few days later with some starter
spray. That eventually got it going. The next time, could not start it
even with that.

Its got a good string spark. The plug seems to be getting wet and is not
fouled. Fuel line is clear as is the air filter. Tried a fresher petrol
mix (super unleaded - from my large can - so probably 8 months old, but
everything else seems to run fine on it)

So what else am I missing?

Parts diagram:

http://www.ereplacementparts.com/mak...245_10188.html


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote:
My chainsaw always used to be very easy to start... turn it over with a
couple of pulls, then ignition on, choke out, throttle in starting
position and off it would go first or second pull.

Now I had it serviced last year, and it was "ok" after that, but not
quite as easy to start. Went to use it this year, and could not get a
peep out of it. Gave up, and tried a few days later with some starter
spray. That eventually got it going. The next time, could not start it even with that.

Its got a good string spark. The plug seems to be getting wet and is not
fouled. Fuel line is clear as is the air filter. Tried a fresher petrol
mix (super unleaded - from my large can - so probably 8 months old, but
everything else seems to run fine on it)

So what else am I missing?

Parts diagram:

http://www.ereplacementparts.com/mak...245_10188.html



Two strokes are just like that. ;-). Alternatively, is it possible that the
flywheel/magneto has slipped on the crankshaft throwing the ignition timing
out?

Tim

On 15/03/2012 22:56, Tim wrote:
John wrote:
My chainsaw always used to be very easy to start... turn it over with a
couple of pulls, then ignition on, choke out, throttle in starting
position and off it would go first or second pull.

Now I had it serviced last year, and it was "ok" after that, but not
quite as easy to start. Went to use it this year, and could not get a
peep out of it. Gave up, and tried a few days later with some starter
spray. That eventually got it going. The next time, could not start it even with that.

Its got a good string spark. The plug seems to be getting wet and is not
fouled. Fuel line is clear as is the air filter. Tried a fresher petrol
mix (super unleaded - from my large can - so probably 8 months old, but
everything else seems to run fine on it)

So what else am I missing?

Parts diagram:

http://www.ereplacementparts.com/mak...245_10188.html



Two strokes are just like that. ;-). Alternatively, is it possible that the
flywheel/magneto has slipped on the crankshaft throwing the ignition timing
out?

Don't know - I suppose it should be possible to see easily enough...
when is the spark supposed to be, just after the piston passes TDC?

Once started the other day it did run ok, although I am not sure it had
quite the power it should have had.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Thu, 15 Mar 2012 23:19:53 +0000, John Rumm wrote:

Don't know - I suppose it should be possible to see easily enough...
when is the spark supposed to be, just after the piston passes TDC?

4 strokes just before, it takes a finite amount of time for the
mixture to ignite and you want the peak of the bang to be just fract
after TDC. This why the spark is advanced as the revs go up on larger
4 stroke engines. Donno if small two strokes have advance, I should
imagine they do.

Once started the other day it did run ok, although I am not sure it had
quite the power it should have had.

Mixture not quite right? two strokes are quite fussy about mixture.

--
Cheers
Dave.

In article ,
John Rumm wrote:
Don't know - I suppose it should be possible to see easily enough...
when is the spark supposed to be, just after the piston passes TDC?

Only two stroke I had was a Vespa years ago and it had rather high advance
in four stroke terms - IIRC, about 30 degrees. No auto advance mechanism.

If the plug is wet, it's either not firing properly or the mixture is too
rich.

--
*When cheese gets it's picture taken, what does it say?

Dave Plowman London SW
To e-mail, change noise into sound.

John Rumm wrote:

My chainsaw always used to be very easy to start... turn it over with a
couple of pulls, then ignition on, choke out, throttle in starting
position and off it would go first or second pull.

Now I had it serviced last year, and it was "ok" after that, but not
quite as easy to start. Went to use it this year, and could not get a
peep out of it. Gave up, and tried a few days later with some starter
spray. That eventually got it going. The next time, could not start it
even with that.

Its got a good string spark. The plug seems to be getting wet and is not
fouled. Fuel line is clear as is the air filter. Tried a fresher petrol
mix (super unleaded - from my large can - so probably 8 months old, but
everything else seems to run fine on it)

So what else am I missing?

Parts diagram:

http://www.ereplacementparts.com/mak...245_10188.html




Look at carburetor, diaphragms (holes in),blockages,and such.

"John Rumm" wrote in message
o.uk...

My chainsaw always used to be very easy to start... turn it over with a
couple of pulls, then ignition on, choke out, throttle in starting
position and off it would go first or second pull.

Now I had it serviced last year, and it was "ok" after that, but not quite
as easy to start. Went to use it this year, and could not get a peep out
of it. Gave up, and tried a few days later with some starter spray. That
eventually got it going. The next time, could not start it even with that.

Its got a good string spark. The plug seems to be getting wet and is not
fouled. Fuel line is clear as is the air filter. Tried a fresher petrol
mix (super unleaded - from my large can - so probably 8 months old, but
everything else seems to run fine on it)

So what else am I missing?

Parts diagram:

http://www.ereplacementparts.com/mak...245_10188.html


Rip the carb off.
Clean thoroughly with a good fuel system cleaner (Redex etc) by soaking the
inside overnight or use a good carb cleaner spray
Blow all orifices clear with airline. Don't prod around with a piece of
wire.
Replace *all* carb interior components that are in a kit for the purpose.
Page H 192 021-151-540 Gasket Set and any others if not included in the set

Check spindles on throttle shaft are not as slack as a sausage up an allwy,
(Air will leak in more so mixture goes to cock)
Renew plug
Renew gaskets

Change ring and head gasket if compression is low and last of all ensure the
casings are not leaking air into the mix


I've rebuilt dozens of thses units when in Hire trade and they are robust

On 16/03/2012 06:30, Nthkentman wrote:

"John Rumm" wrote in message
o.uk...

My chainsaw always used to be very easy to start... turn it over with
a couple of pulls, then ignition on, choke out, throttle in starting
position and off it would go first or second pull.

Now I had it serviced last year, and it was "ok" after that, but not
quite as easy to start. Went to use it this year, and could not get a
peep out of it. Gave up, and tried a few days later with some starter
spray. That eventually got it going. The next time, could not start it
even with that.

Its got a good string spark. The plug seems to be getting wet and is
not fouled. Fuel line is clear as is the air filter. Tried a fresher
petrol mix (super unleaded - from my large can - so probably 8 months
old, but everything else seems to run fine on it)

So what else am I missing?

Parts diagram:

http://www.ereplacementparts.com/mak...245_10188.html



Rip the carb off.
Clean thoroughly with a good fuel system cleaner (Redex etc) by soaking
the inside overnight or use a good carb cleaner spray
Blow all orifices clear with airline. Don't prod around with a piece of
wire.
Replace *all* carb interior components that are in a kit for the
purpose. Page H 192 021-151-540 Gasket Set and any others if not
included in the set


Seems like a good bet. I had the top off the carb the other day, but did
not fully dismantle to see all the gaskets. I will have another go.

Anyone know a good supplier of parts in the UK? Bit annoying that the
gasket set is $7 at the US spars places, and £16 - £20 here!

Check spindles on throttle shaft are not as slack as a sausage up an
allwy, (Air will leak in more so mixture goes to cock)
Renew plug

Plug is pretty new I think...

Renew gaskets

Change ring and head gasket if compression is low and last of all ensure
the casings are not leaking air into the mix

Compression still seems very good. Bore looks smooth and unmarked.

I've rebuilt dozens of thses units when in Hire trade and they are robust

Reassuring to hear.

This one does not get particularly heavy use. It used to belong to a
mate of mine who is (now) a retired builder - so he only used
intermittently for the occasional bit of demolition / roof alterations
etc. I only use it probably half a dozen times a year...

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 16/03/2012 06:30, Nthkentman wrote:

"John Rumm" wrote in message
o.uk...

My chainsaw always used to be very easy to start... turn it over with
a couple of pulls, then ignition on, choke out, throttle in starting
position and off it would go first or second pull.

Now I had it serviced last year, and it was "ok" after that, but not
quite as easy to start. Went to use it this year, and could not get a
peep out of it. Gave up, and tried a few days later with some starter
spray. That eventually got it going. The next time, could not start it
even with that.

Its got a good string spark. The plug seems to be getting wet and is
not fouled. Fuel line is clear as is the air filter. Tried a fresher
petrol mix (super unleaded - from my large can - so probably 8 months
old, but everything else seems to run fine on it)

So what else am I missing?

Parts diagram:

http://www.ereplacementparts.com/mak...245_10188.html


An update for any that are following...

Rip the carb off.
Clean thoroughly with a good fuel system cleaner (Redex etc) by soaking
the inside overnight or use a good carb cleaner spray
Blow all orifices clear with airline. Don't prod around with a piece of
wire.

Had it all apart the other day, and to be fair it looked absolutely
spotless inside - the carb was clean with no deposits, the membranes
looked fine. The cylinder bore and piston rings again perfect condition.
However I carefully blew out all the nooks and crannies just in case
there was debris in there that was not obvious.

Replace *all* carb interior components that are in a kit for the
purpose. Page H 192 021-151-540 Gasket Set and any others if not
included in the set

Not done that yet, since they looked ok. Thought I would see what
difference that made.

Check spindles on throttle shaft are not as slack as a sausage up an
allwy, (Air will leak in more so mixture goes to cock)

Yup, they looked fine.

Renew plug
Renew gaskets

New as of last service and its only done a couple of hours run time
since then. However I gave the plug a good brush clean anyway.

Change ring and head gasket if compression is low and last of all ensure
the casings are not leaking air into the mix

Did not seem to be...

I've rebuilt dozens of thses units when in Hire trade and they are robust

Anyway, I found that I can start it now, but its easier if one lays it
on its right hand side when first trying (so the fuel pipe and feed to
the carb are at the "bottom"). Which makes me wonder if may be suffering
slight fuel starvation. Perhaps the resistance through the clunk and the
fuel filter are higher than they ought to be? Might get a new filter set
and see if that helps.

Now trying to remember if it was stored over the winter with petrol in
it or not... Would letting the fuel system dry out be more likely to
leave residue in the fuel filter? (I am using the red Stihl two stroke
oil in case its relevant)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In message , John
Rumm writes
Anyway, I found that I can start it now, but its easier if one lays it
on its right hand side when first trying (so the fuel pipe and feed to
the carb are at the "bottom"). Which makes me wonder if may be
suffering slight fuel starvation. Perhaps the resistance through the
clunk and the fuel filter are higher than they ought to be? Might get a
new filter set and see if that helps.

Could it be the in tank filter? Is there a non-return valve. My
McCulloch has a foam filter which responds to removal and manual
squeezing.

Now trying to remember if it was stored over the winter with petrol in
it or not... Would letting the fuel system dry out be more likely to
leave residue in the fuel filter? (I am using the red Stihl two stroke
oil in case its relevant)

Certainly get gummy deposits on the carb. jets but you have cleaned
those.

regards



--
Tim Lamb

On 23/03/2012 11:04, Tim Lamb wrote:
In message , John
Rumm writes
Anyway, I found that I can start it now, but its easier if one lays it
on its right hand side when first trying (so the fuel pipe and feed to
the carb are at the "bottom"). Which makes me wonder if may be
suffering slight fuel starvation. Perhaps the resistance through the
clunk and the fuel filter are higher than they ought to be? Might get
a new filter set and see if that helps.

Could it be the in tank filter? Is there a non-return valve. My
McCulloch has a foam filter which responds to removal and manual squeezing.

Yup, that is the one I was thinking off... I shall fish it out and see
what gives ;-)

Now trying to remember if it was stored over the winter with petrol in
it or not... Would letting the fuel system dry out be more likely to
leave residue in the fuel filter? (I am using the red Stihl two stroke
oil in case its relevant)

Certainly get gummy deposits on the carb. jets but you have cleaned those.

regards





--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"John Rumm" wrote in message
o.uk...
On 23/03/2012 11:04, Tim Lamb wrote:
In message , John
Rumm writes
Anyway, I found that I can start it now, but its easier if one lays it
on its right hand side when first trying (so the fuel pipe and feed to
the carb are at the "bottom"). Which makes me wonder if may be
suffering slight fuel starvation. Perhaps the resistance through the
clunk and the fuel filter are higher than they ought to be? Might get
a new filter set and see if that helps.

Could it be the in tank filter? Is there a non-return valve. My
McCulloch has a foam filter which responds to removal and manual
squeezing.

Yup, that is the one I was thinking off... I shall fish it out and see
what gives ;-)

I think you should ask our Rodders, he's bound to know.
Or maybe the loo tennant.
*ahem*

John Rumm wrote:
. Which makes me wonder if may be suffering
slight fuel starvation. Perhaps the resistance through the clunk and the
fuel filter are higher than they ought to be? Might get a new filter set
and see if that helps.

Now trying to remember if it was stored over the winter with petrol in
it or not... Would letting the fuel system dry out be more likely to
leave residue in the fuel filter? (I am using the red Stihl two stroke
oil in case its relevant)


Happened to me - hedgecutter WOULD NOT start till I washed the clunk in
new fuel and blew backwards through it..



--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

On 23/03/2012 11:44, The Natural Philosopher wrote:
John Rumm wrote:
. Which makes me wonder if may be suffering slight fuel starvation.
Perhaps the resistance through the clunk and the fuel filter are
higher than they ought to be? Might get a new filter set and see if
that helps.

Now trying to remember if it was stored over the winter with petrol in
it or not... Would letting the fuel system dry out be more likely to
leave residue in the fuel filter? (I am using the red Stihl two stroke
oil in case its relevant)


Happened to me - hedgecutter WOULD NOT start till I washed the clunk in
new fuel and blew backwards through it..

It may have been that I made a specific effort to drain fluids from it
last year before putting it away for the winter! Seems like just leaving
it on the shelf is a better solution.

(although I need to drain the chain oil otherwise that just oozes out
and makes everything ikky in the vicinity!)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Mar 15, 10:36*pm, John Rumm wrote:
My chainsaw always used to be very easy to start... turn it over with a
couple of pulls, then ignition on, choke out, throttle in starting
position and off it would go first or second pull.

Now I had it serviced last year, and it was "ok" after that, but not
quite as easy to start. Went to use it this year, and could not get a
peep out of it. Gave up, and tried a few days later with some starter
spray. That eventually got it going. The next time, could not start it
even with that.

Its got a good string spark. The plug seems to be getting wet and is not
fouled. Fuel line is clear as is the air filter. Tried a fresher petrol
mix (super unleaded - from my large can - so probably 8 months old, but
everything else seems to run fine on it)

So what else am I missing?

Parts diagram:

http://www.ereplacementparts.com/mak...insaw-parts-c-...

--
Cheers,

John.

/================================================== ===============\
| * * * * *Internode Ltd - *http://www.internode.co.uk* * * * * *|
|-----------------------------------------------------------------|
| * * * *John Rumm - john(at)internode(dot)co(dot)uk * * * * * * *|
\================================================= ================/

A lot of them don't have carburretors any more. The thing that looks
like the carb is in fact a fuel injector. It is worked off the air
pulsations that orginate in the crankcase. So it is a tiny pump with
two little flap valves. The pump diaphragm and valves are in the form
of a sheet of "rubber-like" material that deteriorates and has to be
replaced from time to time.
There is no float/float chamber etc.

A device like this works any way up.

Another likely cause is just muck, blocking something up in the fuel
system.

Oh and check the air vent on the fuel tank. Could be blocked.

On Mar 16, 7:41*am, harry wrote:
A lot of them don't have carburretors any more.

Of course they do, what you've just described is a diaphram carburetor
(works any way up), rather than a float carburetor.

"John Rumm" wrote in message
o.uk...

My chainsaw always used to be very easy to start... turn it over with a
couple of pulls, then ignition on, choke out, throttle in starting
position and off it would go first or second pull.

Now I had it serviced last year, and it was "ok" after that, but not quite
as easy to start. Went to use it this year, and could not get a peep out
of it. Gave up, and tried a few days later with some starter spray. That
eventually got it going. The next time, could not start it even with that.

Its got a good string spark. The plug seems to be getting wet and is not
fouled. Fuel line is clear as is the air filter. Tried a fresher petrol
mix (super unleaded - from my large can - so probably 8 months old, but
everything else seems to run fine on it)

So what else am I missing?

Parts diagram:

http://www.ereplacementparts.com/mak...245_10188.html


It probably needs a new diaphragm
http://www.ereplacementparts.com/pum...9-p-73138.html

Mike

On Fri, 16 Mar 2012 07:58:20 -0000, MuddyMike wrote:

It probably needs a new diaphragm
http://www.ereplacementparts.com/pum...9-p-73138.html

Or the existing one wasn't put back in just the right place so one or
more the flap valves aren't working properly. Had that on my mower,
started to run very rich, took the card of an one of flaps was jamed
into the hole it was supposed to cover. Corrected that and it's been
fine since, several seasons...


--
Cheers
Dave.