What's on your bench today?

[GardenKit]

Am wondering what the science/art (if any) is behind inter changing ignition modules. Spud told me the other day that he's used a stihl module in an allen?? strimmer I think it was - is it just about - if the screw holes fit and it it'll fit into the space give it a go? is there any danger - are they all the same thing but just different shapes? - I know some people here are unlikely to be experimenting with other peoples machines but if it's the difference between a runner and an ornament I'd like to know the ground rules.

 

I have never interchanged coils, for no other reason than I have not needed to. I was amazed to find that spud has, will have to remember that one.

 

If attempting it then make sure the donor coil comes from a machine with the same diameter flywheel. Also check the obvious things such as bolt holes, but also check the coil diameter.

 

When McCulloch changed some coils a few years back the diameter was greater and therefore required some spacers between the coil and the chassis, otherwise something cracked when the coil was torqued down.

 

I think there will be very few interchangeable units though.

[spudulike]

I have never interchanged coils, for no other reason than I have not needed to. I was amazed to find that spud has, will have to remember that one.

 

If attempting it then make sure the donor coil comes from a machine with the same diameter flywheel. Also check the obvious things such as bolt holes, but also check the coil diameter.

 

When McCulloch changed some coils a few years back the diameter was greater and therefore required some spacers between the coil and the chassis, otherwise something cracked when the coil was torqued down.

 

I think there will be very few interchangeable units though.

 

"Amazed":lol: you can get away with a fair bit with coils, once rebuilt one by removing the metal laminated part of a faulty coil and inserted it in to a known good one! All worked very well and was because the original part was EOL.

 

This Allen strimmer is my own and owes me nothing. You need to get the metal parts in the same position as the original and the correct distance from the flywheel.

 

The risk - advancing the ignition significantly enough to pre detonate and destroy the engine - you will hear this in the engine as I found on an 066 I was experimenting with (my own)

 

So in short, if it is a XXXX or bust situation, see if it will work, you are just trying to get a similarly looking coil from another machine to fit in to pretty much the same position!

[mikerecike]

Ok folks - all helpful stuff - much appreciated - and yep it is for those as spud calls it 'xxxx or bust' situations - one question - Barrie mentioned significance of flywheel diameter - is that just so the angle of the coil pickups matches - or is there some other explanation?

[spudulike]

Ok folks - all helpful stuff - much appreciated - and yep it is for those as spud calls it 'xxxx or bust' situations - one question - Barrie mentioned significance of flywheel diameter - is that just so the angle of the coil pickups matches - or is there some other explanation?

 

TBH, as long as the difference in the two sizes isn't stupidly different then it will work, Husky do fit the same coil on the 335 as on much larger machines, Barrie was probably concerned about the metal part of the coil and the way it fits to the flywheel.

 

Just try it, if it works then great, if it doesn't then you haven't lost much. You can use a strobe and degree wheel to check the advance if you are that concerned but it gets a but involved!

[mikerecike]

TBH, as long as the difference in the two sizes isn't stupidly different then it will work, Husky do fit the same coil on the 335 as on much larger machines, Barrie was probably concerned about the metal part of the coil and the way it fits to the flywheel.

 

Just try it, if it works then great, if it doesn't then you haven't lost much. You can use a strobe and degree wheel to check the advance if you are that concerned but it gets a but involved!

 

cheers spud - feel confident to have a go now if it's xxx or b

[Daniël Bos]

My 660 big bore just threw the crankshaft out through the bottom of the case...

I am not that happy about it to be honest.

 

[spudulike]

My 660 big bore just threw the crankshaft out through the bottom of the case...

I am not that happy about it to be honest.

 

 

What part actually let loose? Can't really see from the photo!

[Daniël Bos]

What part actually let loose? Can't really see from the photo!

 

Not quite sure yet, pic is from underneath the saw, crankcase is smashed with bits coming out...

 

Zooming out:

[Rich2484]

My guess would be small end let go and smashed up send big chunks into casing.

 

Pop the pot off and it will soon become clear.

[spudulike]

Just interested as the saws are usually pretty bullet proof, be interesting to see what went ut it looks pretty terminal - useful parts but uneconomical to repair:thumbdown: