2 stroke chainsaw-which part could be causing plug not to spark?

[mart]

I have an Huskvana chain saw. I have tested the plug by resting tip on cylinder head and pulling cord, but no sign of a spark. This plug has not had much use since I fitted it.

The saw is a pull start system, that turns the engine. I don't know if the voltage for the sparkplug is generated from a magnito like mopeds of the 1970s?

I have included a photo of a red & black part. I am wondering if this is the part that creates the voltage to the spark plug, if there is no magnito fitted.

So far I have basically just removed covers. I thought it would be best to eliminate the sparking issue before dismantling the saw any further, and get some advice from the forum if anyone can help?

 

[jordhandson]

My money will be on the coil, been there a few time and got the T shirt

 

[dobbslc]

Also worth checking the continuity or not of the kill switch.

 

[mart]

My money will be on the coil, been there a few time and got the T shirt

Will the coil be that black & red plastic component in my photo?

 

[jordhandson]

Will the coil be that black & red plastic component in my photo?

yep

 

[mart]

Thanks

 

[Migmac]

Try a different plug.

 

[Rkweld]

Try a different plug.

Or anything conductive that will show a spark against the casing from the ht lead.

 

[Blobber]

The coil should be a set distance from the flywheel which is very small, think its something like the thickness of a sheet of paper, when stuff stands around you get rust build up on the coil so it may just need a clean

 

[Rkweld]

Also when the bearings go the flywheel can pull away from the coil or get closer and eat it aswell.

 

[Tinbasherdan]

My first port of call would be the kill switch, then the coil , then it gets more serious

 

[Screwdriver]

The very first thing I would do is really check to make sure there is no spark. They can be tricky to see. Make a good earth (not on the paint) and test it in a darkened area.

 

[Bornfree]

Pull the kill switch wire off the coil as the switch normally earth's to stop.

 

[Migmac]

In forty years of working chainsaws don’t think I’ve ever had an ignition module fail.

 

[mart]

The coil should be a set distance from the flywheel which is very small, think its something like the thickness of a sheet of paper, when stuff stands around you get rust build up on the coil so it may just need a clean

Thanks for drawing my attention to that. It had not ocurred to me that the rotating flywheel passing closely to the coil is an integral aspect of creating the spark until you mentioned it. The surfaces look quite clean, but it is a valid point that you make, thank you.

 

[Migmac]

The gap is 0.2mm - 0.3mm or 0.008 - 0.012

 

[mart]

The very first thing I would do is really check to make sure there is no spark. They can be tricky to see. Make a good earth (not on the paint) and test it in a darkened area.

After seeing your post last night I went back to the 'bench' ......kitchen worktop after turning all the downstairs lights off. Sure enough as you predicted, there was indeed a spark. Not a big one but definitely a spark.

I guess this means I need to check the carb and check there are no any blocked jets. Jets are generally very small inside. Being on a carb as small as this one they must be minute.

I've not yet worked out how to remove the carb. There will be a way, but at the moment it is not an obvious one, visible screws etc.

 

[James1979]

What model is it?

 

[Bornfree]

Pour a little petrol through the carb or spark plug hole and quickly try to start it with open throttle and no choke.

 

[Screwdriver]

99/100 it's going to be an issue with fuelling. I generally use a quick squirt of easy start and if there's a problem with the carb, hit ebay for a replacement (cheap as chips). Once you have fiddled around stripping cleaning, swearing and failing, your new carb will arrive.