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?
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..
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.
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?
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 :)
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.
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