SUCCESS!!! Just repaired Stihl 045/056 Bosch electronic ignition!!!!!

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Absolutely outstanding thread, Foggy!!!:clap:

Now as Rokon wistfully (and wishfully) mused...

From all the reading in this post, this repair only applies to the BOSCH version of ignition.

Now, I hope someone can figure out the SEM problem.... :-(

No kidding! Same exact symptom (for the most part). Evidently a bit more of a challenge getting to the component level for analysis and repair, tho.

BTW, most of us would strongly suggest using mix vs. starting fluid when attempting to start a stubborn saw (or one with suspected fuel delivery issues)!!! No lubrication in starting fluid and damage can occur to the top end if the saw over-revs or is run too long on it.

But should you care to take a stab at one of the SEM modules, I'd be glad to send one your way for dissection...., as I'm sure would many others as well!!!
 
Does anyone know if the husky 2100-2101 Bosch ignition is the same as this one repair wise?

Yes they are.

I thought that the Husky 1100-2101 series used SEM and FEMSA ignitions (with different flywheels and starter covers for each of those two ign types). Hadn't heard/read about a Bosch ignition for these before. Is the Bosch the same as the FEMSA?
 
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Images of the job as it took place, my soldering is not the prettiest but is well stuck, and will be sealed up with hot glue tomorrow.


Sent from my iPhone using Tapatalk
 
Bill Melhorn--

I encourage you to rebuild your ignitions. The fix is well described along with pictures. Essentially all one needs to do is gently scrap off a small amount of potting material AT THE LOCATION SHOWN IN THE PICTURES, make a small cut in the exposed copper run and solder a wire to it. The rest of the fix is assembly along with mounting the capacitor. THIS IS NOT ROCKET SCIENCE, anybody who purchases a soldering iron design for electronic work (about 25 watts) along with solder sold specifically for electronics (flux in the core) can easily accomplish these things.

You asked about the kill wire elsewhere. What I recommend doing is to clip the kill wire off the ignition but leave about 1/4-3/8" of wire protruding. Clean that small piece of remaining wire and solder a new, stranded, insulated wire onto the cleaned stub. Cover the new solder joint with anything you can get your hands on--- epoxy, caulking compound.... you get the idea.

If you do replace the wire, I highly recommend purchases a simple toggle switch from Radio Shack or elsewhere to replace the POS shutoff switch on the saw proper. Not only does the POS shutoff wire short out the ignition because the insulation used in Germany when the saw was made, attempted to please the Greenies and it self destructs in a heated enviroment, but the stinking switch can fail shorted or open.

Give those ignitions a try and remember, the modification REMOVES an internal capacitor and replaces it with a new externally mounted capacitor. And the new capacitor is mounted in a cooling air stream.

Foggy
 
Bill Melhorn--

I encourage you to rebuild your ignitions. The fix is well described along with pictures. Essentially all one needs to do is gently scrap off a small amount of potting material AT THE LOCATION SHOWN IN THE PICTURES, make a small cut in the exposed copper run and solder a wire to it. The rest of the fix is assembly along with mounting the capacitor. THIS IS NOT ROCKET SCIENCE, anybody who purchases a soldering iron design for electronic work (about 25 watts) along with solder sold specifically for electronics (flux in the core) can easily accomplish these things.

You asked about the kill wire elsewhere. What I recommend doing is to clip the kill wire off the ignition but leave about 1/4-3/8" of wire protruding. Clean that small piece of remaining wire and solder a new, stranded, insulated wire onto the cleaned stub. Cover the new solder joint with anything you can get your hands on--- epoxy, caulking compound.... you get the idea.

If you do replace the wire, I highly recommend purchases a simple toggle switch from Radio Shack or elsewhere to replace the POS shutoff switch on the saw proper. Not only does the POS shutoff wire short out the ignition because the insulation used in Germany when the saw was made, attempted to please the Greenies and it self destructs in a heated enviroment, but the stinking switch can fail shorted or open.

Give those ignitions a try and remember, the modification REMOVES an internal capacitor and replaces it with a new externally mounted capacitor. And the new capacitor is mounted in a cooling air stream.

Foggy
 
While waiting for capacitors to show up, I removed the kill switch wire for a module I had, making sure no remains were touching the metal case, put the flywheel on securely over the keyway, put the flywheel back on, tightened the nut with impact wrench, then turned the crank counterclockwise with a drill, have spark now. Assembled the saw and fired on the 4th pull. With no kill switch wire, I could securely screw the module ono the spark plug wire. I shut it down by pulling the boot off the spark plug with gloved hand, using the choke makes it harder to restart. Previous post warned about using starting fluid, but what I get at Walmart has a top end lubricant. Questions: could I replace the kill switch wire by removing some of the potting like you did to get at the capacitor? And could I put butt style connectors on the kill switch wire as well as the capacitor wire to be able to use/test other modules (I have 6), still enabling me to to screw the module onto the spark plug wire?
 
While waiting for capacitors to show up, I removed the kill switch wire for a module I had, making sure no remains were touching the metal case, put the flywheel on securely over the keyway, put the flywheel back on, tightened the nut with impact wrench, then turned the crank counterclockwise with a drill, have spark now. Assembled the saw and fired on the 4th pull. With no kill switch wire, I could securely screw the module ono the spark plug wire. I shut it down by pulling the boot off the spark plug with gloved hand, using the choke makes it harder to restart. Previous post warned about using starting fluid, but what I get at Walmart has a top end lubricant. Questions: could I replace the kill switch wire by removing some of the potting like you did to get at the capacitor? And could I put butt style connectors on the kill switch wire as well as the capacitor wire to be able to use/test other modules (I have 6), still enabling me to to screw the module onto the spark plug wire?

There is no room inside the ignition to easily use a butt crimp connector that is why I suggested clipping the original wire at about 1/4-3/8" above the potting material. Why do you want to be adventurous and needlessly dig into the potting material in an unknown area? Consider the risks! That is why I carefully photographed exactly where I wanted potting material removed in the "fix" pictures.

It appears your problem was the kill wire was shorting out and not the capacitor. Should you change the capacitor as described???? Well the old rule I operated by was if its not broken, don't fix it. However..... reality sets in when one considers the huge number of ignition failures attributed to a capacitor buried in potting. So my friend..........the choice is yours. Fix me now or fix me later. OH--- I use the choke on mine although I did replace the kill wire. But my stinking POS switch is shorted and I just don't feel like replacing it but if I do in the future, it will be with a simple single pole single throw toggle switch, not an original part.
 
There is no room inside the ignition to easily use a butt crimp connector that is why I suggested clipping the original wire at about 1/4-3/8" above the potting material. Why do you want to be adventurous and needlessly dig into the potting material in an unknown area? Consider the risks! That is why I carefully photographed exactly where I wanted potting material removed in the "fix" pictures.

It appears your problem was the kill wire was shorting out and not the capacitor. Should you change the capacitor as described???? Well the old rule I operated by was if its not broken, don't fix it. However..... reality sets in when one considers the huge number of ignition failures attributed to a capacitor buried in potting. So my friend..........the choice is yours. Fix me now or fix me later. OH--- I use the choke on mine although I did replace the kill wire. But my stinking POS switch is shorted and I just don't feel like replacing it but if I do in the future, it will be with a simple single pole single throw toggle switch, not an original part.
 
Shoulda known. Cut down 17" dead fir, then cut 16 rounds off the big end . Stopped the saw to reposition my log holder. Saw wouldn't start: no spark. Now I wait for the capacitors to arrive from China. I misspoke earlier, thinking of using bullet connectors on the wires so I can take tham apart and swap modules to check them after installing the capacitors and removing just enough of the potting to solder a new kill wire since I cut it off too short like a dummy. thanks tons for the input. Where do I send beer (soda) money? seriously.
 
Shoulda known. Cut down 17" dead fir, then cut 16 rounds off the big end . Stopped the saw to reposition my log holder. Saw wouldn't start: no spark. Now I wait for the capacitors to arrive from China. I misspoke earlier, thinking of using bullet connectors on the wires so I can take tham apart and swap modules to check them after installing the capacitors and removing just enough of the potting to solder a new kill wire since I cut it off too short like a dummy. thanks tons for the input. Where do I send beer (soda) money? seriously.

I was going to suggest removing the wire from the kill switch if it was still wired but from your note above, appears the wire is cut at the potting. If you have the wire cut too short, you should be safe to dig out enough potting surrounding the cut wire. Then you can solder a new stranded wire to the exposed stub. Good luck with it :)
 
I was going to suggest removing the wire from the kill switch if it was still wired but from your note above, appears the wire is cut at the potting. If you have the wire cut too short, you should be safe to dig out enough potting surrounding the cut wire. Then you can solder a new stranded wire to the exposed stub. Good luck with it :)
 
I found out this morning that when you look at the instructions with pictures in page 3, they are pretty small, but if you log in, they magically become full size, making your directions crystal clear. And using the choke to stop the saw requires 2 pulls on the starter when restarting instead of one if you have a kill switch. Think I'll not bother with fixing the kill switch.
 
Hi foggy. I have the same Bosch ignition in my Husqvarna 285. It's identical to the 056 units. My question is this, does an ignition that fires weak have anything to do with the capacitor? Mine fires but the saw doesn't start and all else is well. Under full advance the increase in timing should make the saw hard to pull over but no change from full advance to retardation of the ignition timing when rotating the armature. I assume the spark is to weak under compression.
 
Hi foggy. I have the same Bosch ignition in my Husqvarna 285. It's identical to the 056 units. My question is this, does an ignition that fires weak have anything to do with the capacitor? Mine fires but the saw doesn't start and all else is well. Under full advance the increase in timing should make the saw hard to pull over but no change from full advance to retardation of the ignition timing when rotating the armature. I assume the spark is to weak under compression.

Probably not. Silly question/statement.... I presume the shaft key for the flywheel is OK.

Before you do much more...... try using starter fluid. Just spray a little into the carburetor and give it a try....outside of course. Let us know if the saw responds.
 
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