Partner S55 Ignition - DIY Ignitron?

[fredrej]

Hi - first post for me after years of following the forum for it's huge knowledgebase.

I have a Partner S55 saw (1979 model year), that died on me. No spark anymore. Coil seems dead, so I have a replacement on the way. But: If the "Ignitron" module is toast, is it feasible to make one for myself? I don't think it is available as a part anywhere.

I've seen "integrated" variants from Briggs called "Magnetron" which I presume does what I want it to - a coil with a transitorized switch providing spark.

My question: Has anyone ever replaced an Ignitron ingnition with something else, or built their own? Advice will be greatly appreciated!

I know my electronics, but have limited experience with ignition systems. Ignition timing might be an issue? Does the ignitron module somehow retard or advance the timing, or is it simply a switch, with fixed timing based on the flywheel magnets?

Best regards,
Fredrik, Norway.

 

[pioneerguy600]

This is a link to a thread where the switch mechanism was identified and a fix found for returning it to working again,click on below.

http://www.arboristsite.com/communi...ectronic-ignition.256095/page-14#post-5233378

 

[Modifiedmark]

If your talking about the Ignitron module under the handle, then yes you can replace that with a Nova module. I just done that on a P100 that came to me with the module dead on it.

I also found you can replace the complete Thyristor ign on a Partner 55 with a coil from a Husqvarna 55 and am fairly certain it would replace the coil on the Ignitron ign as well.

Overall that would probably be your best bet to replace the whole ign with the Husky style one piece unit. The high tension lead is a bit close to the top cover but it clears without any issues.

 

[fredrej]

This is a link to a thread where the switch mechanism was identified and a fix found for returning it to working again,click on below.

http://www.arboristsite.com/communi...ectronic-ignition.256095/page-14#post-5233378

That's useful - thanks!

 

[fredrej]

If your talking about the Ignitron module under the handle, then yes you can replace that with a Nova module. I just done that on a P100 that came to me with the module dead on it.

I also found you can replace the complete Thyristor ign on a Partner 55 with a coil from a Husqvarna 55 and am fairly certain it would replace the coil on the Ignitron ign as well.

Overall that would probably be your best bet to replace the whole ign with the Husky style one piece unit. The high tension lead is a bit close to the top cover but it clears without any issues.

Thank you both, helpful information. I did not know the nova (or Oregon etc.) style ignitions existed as aftermarket parts. Looks like my workhorse S55 will be back into useful service after all


One question I have is this: When you say "husky style one piece unit" do you mean that the husky 55 (Rancher?) has a physically similar unit, where the electronic switching is potted into the coil assembly? So I would just need to do some rewiring and be good to go?

 

[Modifiedmark]

Out of curiosity today, I done some more checking, and the Husky 55 style coil will also bolt right in place of the Ignitron coil just like it dose in place of the Thyristor coil.

And yes, Husky 50, 55, 55 rancher, 261 and a bunch of others There is no rewiring needed, all you have to do is hook your kill switch wire to the coil spade terminal. You may have to put a spade terminal on your kill switch wire if it don't have one as I have seen some with ring terminal connections.

I found out before the 55 cc Partner flywheels must be the same exact diameter as the Husky 55 flywheel as the contour of the coils core matched up perfectly.

What I tried today was to replace the Ignitron coil on my P70 with a Husky 55 coil and it worked and ran just fine. That said the contour of the core on the Husky 55 coil is not a exact match to the 70cc Partner flywheel as it is a bit larger dia.

If I was going to leave the Husky 55 electronic coil on it, I would either grind/trim the core to match the flywheel contour or remove the coil from the core and press it onto the Partner core.

Here is a picture of the Husky 55 coil on a 55cc Partner. You can see the core matches the 55cc flywheel contour like it is suppose to.

Like I said, it works fine and would be the way I would go to fix it.

 

[fredrej]

Out of curiosity today, I done some more checking, and the Husky 55 style coil will also bolt right in place of the Ignitron coil just like it dose in place of the Thyristor coil.

And yes, Husky 50, 55, 55 rancher, 261 and a bunch of others There is no rewiring needed, all you have to do is hook your kill switch wire to the coil spade terminal. You may have to put a spade terminal on your kill switch wire if it don't have one as I have seen some with ring terminal connections.

I found out before the 55 cc Partner flywheels must be the same exact diameter as the Husky 55 flywheel as the contour of the coils core matched up perfectly.

What I tried today was to replace the Ignitron coil on my P70 with a Husky 55 coil and it worked and ran just fine. That said the contour of the core on the Husky 55 coil is not a exact match to the 70cc Partner flywheel as it is a bit larger dia.

If I was going to leave the Husky 55 electronic coil on it, I would either grind/trim the core to match the flywheel contour or remove the coil from the core and press it onto the Partner core.

Here is a picture of the Husky 55 coil on a 55cc Partner. You can see the core matches the 55cc flywheel contour like it is suppose to.

Like I said, it works fine and would be the way I would go to fix it.
View attachment 422804

Thanks a lot - that clarifies the physical fitting part. Do you know if the husky coil has the electronics potted into the coil itself? If my ignitron module (small black piece in the handle of the saw) is toast, I'm worried I'll either burn the new coil, or that it will not produce spark anyway (since there is no switch to collapse the field in the primary windings, there will be no voltage produced by the secondary..)

Again, thanks for the great effort! Let's hope this is useful for the other forum members as well.

Best regards,

Fredrik.

 

[Modifiedmark]

Yes the Husqvarna coil is all self contained.

It seems that most the time its the ignitron module under the handle is what goes out most times. I think the Ignitron coil itself mostly just a points style coil and don't really fail that often.

Like I posted earlier, the Nova module worked fine on my P100 with its stock Ignitron coil.

I said Nova as that is what I used, I think the Oregon brand is also the same. The only reason I didn't go the Husky coil on it is the P100 flywheel is much larger and won't match up with the core. I do believe the Partner 100 based cutoff saws used a one piece coil/module that would work on the 85 and 100 cc saws.

Like I said, the Husky 55 coil is a bolt on for the 55 cc saws.

 

[fredrej]

Yes the Husqvarna coil is all self contained.

It seems that most the time its the ignitron module under the handle is what goes out most times. I think the Ignitron coil itself mostly just a points style coil and don't really fail that often.

Like I posted earlier, the Nova module worked fine on my P100 with its stock Ignitron coil.

I said Nova as that is what I used, I think the Oregon brand is also the same. The only reason I didn't go the Husky coil on it is the P100 flywheel is much larger and won't match up with the core. I do believe the Partner 100 based cutoff saws used a one piece coil/module that would work on the 85 and 100 cc saws.

Like I said, the Husky 55 coil is a bolt on for the 55 cc saws.

Husky 55 coil ordered Do you know the air gap spec for this coil/saw? Is there a universal standard value?

 

[Modifiedmark]

Just set the air gap at .012" and you will be good to go.

The spark plug lead will be too long, but in case you don't know, you can just unscrew it from the module, cut it off then screw it back on.

 

[Koogan]

Just set the air gap at .012" and you will be good to go.

The spark plug lead will be too long, but in case you don't know, you can just unscrew it from the module, cut it off then screw it back on.

Very helpful suggestions Mark. I have a Partner F 55. It has no spark. I tested the coil with an ohm meter and it tested correctly. The separate ignition module does not produce current when I pass magnet past it. I can't find one. Do you think the Husky 55 will fit and then I can do away with my coil. Is it possible to replace the electronic components in my ignition module described as a thyristor system with new components if they can be cut open and tested.

 

[KASH]

I have done two conversions first saw Partner R420t I put the one piece coil from a Partner cutoff saw.Has worked flawless for a couple hundred cords of wood over five years or so.
Second saw Partner P70 I put a coil from a Husky 51 it has also worked flawless.
when they changed from two piece to one they just combined the two pieces into one.If I was just changing the trigger piece in the handle I would use the Kawasaki module as I have had good luck with them.It is much easier to use the one piece Husky coil.
Something too watch for is if you are changing too the Husky coil make sure you take the trigger unit out of the handle as it is hooked up to the stop switch and if it is grounded your SOL I learned it the hard way.
Kash

 

[Koogan]

I was hoping for that solution. Does the one piece module fit into the existing mount holes for my electronis unit or do you have to fab a plate to match up? I take it the coil becomes redundant. I ahve a Partner K700 Active 2 cut off saw so I could compare those.

 

[Koogan]

Both of my modules are side by side. The switch near the handle just grounds the electronic module so i think i can keep it as it. Its a lot like my Jonsred saws.

 

[Koogan]

I have tried the ignition module from my Partner cut off saw. It is an exact fit. I expect it will work and I will order another to replaceit on K700. Thank Kash.

 

[Koogan]

My K700 module fits

 

[Ivica S.]

Ignition thyristor