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2 stroke hedge cutter

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Muddymike

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Jul 16, 2008, 11:42:46 AM7/16/08
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Anyone here knowledgeable about 2 stroke engines on things like hedge
cutters?

Thing is my Kawasaki hedge cutter stopped whilst ticking over and refused to
re-start. It had a spark, but seemed to be flooding, so I replaced the
diaphragms in the carburettor as this has cured the flooding problem in the
past. Now despite a new plug it refuses to start. Fuel seem ok, as the plug
now gets wet but not too wet. Spark is there. But no start? It has two
adjustment screws on the base of the carb (as well as the tickover screw)
any thoughts on a good starting position for these?

Mike


Palindrome

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Jul 16, 2008, 12:45:49 PM7/16/08
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It isn't old fuel is it? If so, I would drain everything out and replace
with fresh petrol mix.

You need an aerosol of petrol + spark + vacuum at the right time..
No aerosol - No good. No petrol - No good. No spark - No good. No timing
- No good. Too slow a "pull" = no vacuum. So you need to check for each
of these.

(I have a starter motor with a rubber cone on the end that I use to
start such tools - I just can't pull hard enough. I've cut suitable
holes over the flywheel on my chain saw, hedge cutter, etc and just
push, press the power switch and even the most reluctant one leaps into
life. That solves the "vacuum" problem for me)

However, assuming that physical strength isn't your problem, spraying
Easy Start into the air intake is the next step. Some people use neat
petrol in a trigger-push aerosol bottle to do the same - but please,
nowhere near anything inflammable if you must.. If that works - then you
know it is carburettor problems.. If it doesn't, it's the electrics.

Assuming that machine has standard coil under the flywheel, then a spark
problem is going to be a dead capacitor or a tracking plug. Replacing
the plug is the easiest...

If all that lot is OK, then you are back into the carburettor. But I
suggest that you eliminate the rest and come back if needed..

Good Luck..

--
Sue


cj

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Jul 16, 2008, 4:27:23 PM7/16/08
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Hi IIR most of these engines use a diaphragm carb' (Keihin or similar) they
have 2 running screws 1 for mixture & 1 for slow running start by screwing
both in fully then back off 2 - 2 1/2 turns as a start.
2 strokes can be a pain to start if not used for a while as they use the
crankcase to pressurise the fuel (separating the oil for lubrication)
[unless its a Suzuki which use a patented oil feed system ] .
A few tips to try :
Don't assume that if the plug sparks out of the cylinder it will inside some
times plugs fail under pressure.
Remove all fuel (disconnect the fuel line) remove the plug ,turn over engine
until no petrol or vapour is present, replace plug and turn over.
If the vapour is good fuel the remnants in the crankcase will allow the
engine to fire and may even run for a short time.
If the engine is dry add a drop of fuel (teaspoon full max) through the
spark plug hole and turn over slowly a few times refit plug and try to
start.
If success tune carb' or look for fuel leaks.
If all this fails examine the crankcase for cracks or seal breaches.

HTH

CJ


Muddymike

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Jul 17, 2008, 3:17:39 AM7/17/08
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Thanks Pal and "cj"
You have given me a lot to check.
How fresh is fresh when talking about petrol these days. The fuel I am using
was bought on the last weekend of May and is the last few litres from a 20
litre jerry can. It works fine in the 4 stroke machines but are 2 strokes
more sensitive?

Mike


Palindrome

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Jul 17, 2008, 4:05:52 AM7/17/08
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I suspect the main reason for using "fresh" mix is that you are
absolutely sure that it is ok. Whereas stored fuel could have
selectively lost some of the more volatile compounds, could have got
contaminated, etc. This could particularly be the situation using the
last few litres from a tank, where heavier contaminants may be more
likely to be present.

As to whether 4 stroke machines are more sensitive - its a bit academic
as individual engine designs are so varied. Some are designed to run off
almost anything liquid and inflammable. Some are far more demanding. I
can't pull start any of them :)

--
Sue

cj

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Jul 17, 2008, 5:38:35 PM7/17/08
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My strimmer still runs off a plastic can of 2 stroke I mixed 18 mths ago but
as Sue points out things settle and if left open to air the fuel can
evapourate in certain circumstances.
BTB Sue try a Sachs Dolmar Rotary if they still make them a 3 rotor 2 stroke
.no compression to mention swings easily starts first pull if tuned
correctly and goes like the preverbial S*&t of a shovel.

CJ


Palindrome

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Jul 17, 2008, 6:02:57 PM7/17/08
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Wow, I had no idea that there were Wankel engined chainsaw. That's
something to ask Father Christmas for..

At present, once started, I leave mine running - which wastes fuel and
is really dangerous. If it stops, I have to take it back to the starter
and its car battery. When the fuel runs low/out, I have to take it back.
It's a pain. Could be an even worse one if it bites me as I am carrying
it around.

No one makes pink chain saws with flowers on... you'd think the only
people that buy and use the things are lumberjacks, swinging from tree
to tree..

--
Sue

Muddymike

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Jul 18, 2008, 1:52:59 AM7/18/08
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"Palindrome" <m...@privacy.net> wrote in message
news:kkPfk.252114$Ev5....@fe09.news.easynews.com...

>
> No one makes pink chain saws with flowers on... you'd think the only
> people that buy and use the things are lumberjacks, swinging from tree to
> tree..

You will be telling us next that you do so in "High heels, suspenders and a
bra"

Mike
(a Monty python fan)

Kevin

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Jul 18, 2008, 3:24:11 AM7/18/08
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now that's an image :-) and if you do post some pics

--
Kevin R
Reply address works

Muddymike

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Jul 21, 2008, 4:49:45 AM7/21/08
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I have tried all the advise I was given and the thing still won't start. It
seems that when I pull it over by hand I get a weak spark. Taking a bit of
Sue's advise I removed the pull start and used an electric drill onto the
flywheel nut. This spins the engine over well, but at these higher revs I
get no spark at all. I have tried isolating the cut of wires and still have
no spark. So I guess something in the ignition system has died.

Mike


robgraham

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Jul 21, 2008, 5:53:22 AM7/21/08
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"Muddymike" <MikeR...@mattishall.org.uk> wrote in message
news:JoydnWikaNYs0BnV...@brightview.com...

It sounds like a condenser problem. See if you can check this or buy a new
one (can't be very expensive).

Rob Graham


Muddymike

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Jul 21, 2008, 6:04:57 AM7/21/08
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"robgraham" <rttgra...@btinternet.com> wrote in message
news:tP-dnQ7r1bMUwRnV...@bt.com...

It has electronic ignition and I have already replaced the condenser like
little metal box thingy cost me £16

Mike


robgraham

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Jul 21, 2008, 7:28:05 AM7/21/08
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"Muddymike" <MikeR...@mattishall.org.uk> wrote in message
news:59adnTxKxIbzwhnV...@brightview.com...

Mmmm.


Alang

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Aug 18, 2008, 3:02:51 PM8/18/08
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