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

[Woodslasher]

Greetings! Seems there are many success stories about this fix so hoping my $10 garage sale find will be one of them! My 056 super does have the bosch ignition however it seems to have gotten hot and the potting has melted and expanded leaving a sticky black substance all inside the flywheel. I have yet to try and dig the potting out but is this likely to sabotage any potential chances of a fix?

I'd see if you can find the saegenspazi replacement coil if your coil is melted.

 

[jerrycmorrow]

Great thread. Subscribing

 

[aschaumburg]

I'd see if you can find the saegenspazi replacement coil if your coil is melted.

I tend to agree but still looks like there is a shipping issue. Has anyone had a successful experience with the saegenspazi replacement and care to share?

 

[PogoInTheWoods]

Reports have varied regarding the Saegenspezi modules. And with all due respect, this thread is about repairing the Bosch ignitions. Several threads exist which address other approaches to reviving 045/056 ignitions.

But considering your description of what sounds like some excessive heat at the coil/flywheel, and not to sound too discouraging, I'd be concerned about other potential problems with the saw before getting too wrapped up in the ignition just yet.

 

[WI-790R]

That is cool! I just yesterday, x-rayed a failed doughnut-shaped one from my 076 Super. Plan to try and draw out the board schematic, etc. I have the pics at work and will be back there on 11/30. Will share them here.

 

[aschaumburg]

Reports have varied regarding the Saegenspezi modules. And with all due respect, this thread is about repairing the Bosch ignitions. Several threads exist which address other approaches to reviving 045/056 ignitions.

But considering your description of what sounds like some excessive heat at the coil/flywheel, and not to sound too discouraging, I'd be concerned about other potential problems with the saw before getting too wrapped up in the ignition just yet.

Thanks, I'll dig around for those other links.

It spins over freely, has compression and fuel. Kinda trying to decide if I part it out or put a few bucks into seeing if I can get spark and it to pop.

 

[PogoInTheWoods]

Any chance you have some pics of the melted module?

 

[pjotrxxxx]

Many here in the forum may have read my recent posts regarding the Bosch electronic ignition. My 056 pooped the bed or better still make that my lawn while I was in the middle of clearing trees. And yes, problem was no spark. I have also read numerous posts stating that the cause is "coil opening while hot." Well folks, I doubt its either of the magnetic devices in the ignition needed for it to function. My advice....save your money, do not replace the high voltage transformer or the charging inductor. They are the least likely to fail but my saw's component that did fail operated on the border of component death. Just a matter of time before they all fail.

The problem resides in the potted electronics, that area between the charging inductor and the high voltage transformer. AND THEY CAN BE REPAIRED! NO so called little fix all boxes to take the place of the original ignition, no retiming, just bright blue spark or at least that is what mine now displays in my basement after repair.

Now here is a gutcha. If somebody will part with a junk ignition which I need for two reasons, I will take pictures of how to make the repair, provide written instructions and explain which part needs to be purchased. I purchased my part on EBay, bought 10 of them, delivered for under $7 bucks.

The reason I need another ignition is to verify this is the common fault that folks experience with an ignition failure. I think it is but I feel uncomfortable with a repair sample of 1. The next reason is mine is too ripped apart (it functions though) to take pictures for repair instructions. If anybody in the forum has one they want to contribute to the cause, I gladly pay for shipping and handling. This is a chance for every 045/056 with bad ignitions to get their saw running again. Mine now works.... I have not yet started the saw, just got may parts in this afternoon and rushed to install one. Just too anxious to put that off.

So there you have it. I believe all the failures or at least the greatest number of them are from the same component failure. Too many guys have seen their great 045/056 go belly up with no practical repair. There is hope guys and it is free but I am not going to even attempt to describe how to make the repair until I can do it properly. And you do not need electrical skills although you will need a soldering iron and solder purchased from Radio Shack or some other place that sells electronic stuff. The repair probably take around an hour to complete. You cannot use plumbing solder. So lets see how much interest this thread excites if any.

Foggy

Hi, I'am from Holland (Europe) and have a 056 AV chainsaw I bought long ago when I was still a young man. I have used this heavy machine rarely (in France where I live most of the time now) and even less when a problem you describe started manifesting itself. After a more or less difficult start it works fine for 5-10 minutes then it stops and it is impossible to start it till it completely cools off. Had it "repaired" in France but probably a typical "French repair", didn't really get much better.So could you sent me some more details of how to replace this capacitor, cause I feel this might be the ideal solution without costing me a fortune? Thx. Peter

 

[WI-790R]

That is cool! I just yesterday, x-rayed a failed doughnut-shaped one from my 076 Super. Plan to try and draw out the board schematic, etc. I have the pics at work and will be back there on 11/30. Will share them here.

Here is a pieced-together bunch of x-rays of my failed donut shaped module from an 076 Super. I think the two box-shaped components in the 1 o’clock position, are film capacitors. I was expecting a more sizable capacitor in there someplace, assuming this is some version of a CDI.

I also assume the metal can package is an SCR, and that the —| |— looking parts are diodes.

I have not physically dug in to it yet.

 

[cweinberg33]

So do we have a succus rate higher than two units so far?

Just wondering as I know Axlr8 has a few of these including one of mine that could probably benefit from this fix.

cheers!

Yes, I just fixed a friends 041 av electronic. First attempted the ground wire repair and the saw would run for 20 to 30 secs and just cut out... So the next step was necessary digging out the old capacitor connections. Then I opened up the epoxy filler, cut the circuit and then soldered a new wire.. I sealed everything up with hot black glue, assembled and finally soldered the wires to the new capacitor. Then routed wires and hot glued the capacitor on the black plastic shield under the air filter assembly. Saw works like a champ now. Thanks everyone who provided the input for the repair. Feel free to ask any questions concerning my repair.

 

[PogoInTheWoods]

What exact capacitor did you use?

 

[Chazz]

Hi everyone. Newbee here. I joined as I was very interested in this thread - "SUCCESS!!! Just repaired Stihl 045/056 Bosch electronic ignition!!!!!" by @foggysail I have this problem and intend to try this repair to my Stihl 041 AV Electronic chainsaw as it would appear to be the same Bosch unit. This saw was a beast after I set it up a few years ago and was running really well. Recently started shutting off after 10 or so minutes. Now it has no spark at all. I have checked all the usual things like plug, HT lead, cut off switch and associated wiring. I had assumed it would be the coil but found it was permanently wired into the electronic unit as was the primary coil (if that is the correct term) so came on line to see what my options were. Thankfully I found this thread and here we are. I need to go now and read the whole thread and do some studying :0) I would appreciate some guidance on the capacitor as I cannot seem to find the correct one. Has this capacitor been upgraded? Any updates will be greatly appreciated. Many, many thanks to Foggysail, Lang may you have fair winds and following seas my friend.
All the best from Chazz in Windy, Wet but Bonnie Scotland.

 

[Chazz]

Yeeha!!! Another success. I have replaced the capacitor on my Stihl 041 AV Electronic chainsaw with https://www.ebay.co.uk/itm/392966257274?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649 When I fired up the saw I instantly knew it was a success as the engine sounded much crisper and I had to reduce the idle as it was running fast. Today I used it for a couple of hours and it never missed a beat and devoured a large hardwood trunk I had been working on when it packed up. Well chuffed and well grateful to foggysail for his knowledge and generosity in giving this information.
For anyone repairing their 041 with bosch ignition I have included photo's and a few instructions should they need them. I used a soldering iron with quarter inch blade for softening the potting as this gave more control on the location of the heat. Unlike the original fix, I only ran one wire (the white one) from the electronic ignition,taking it under the coil and out the flywheel housing via the (black) kill switch wire grommet. you have to file a small groove in the alloy casting to let the wire through to the grommet and if you take your time you can file just enough to give a snug fit on the wire insulation when the ignition unit is screwed down avoiding unnecessary movement (rubbing) of the wire (Sorry forgot to take a photo of this) Then under the plastic shield. I took the other (white) ground wire from the capacitor to one of the four screws that attach the pull start/petrol tank housing to the saws main body which has a high continuity to ground. I attached the capacitor to the black plastic shield which sits under the carburetor as I think this would have a good flow of cool air. It also sits nicely into this space if you butt it against the small ridge in the plastic. It is sufficiently secured with this ridge and the two cable ties. Make sure your cable tie "heads" are below the top of the Capacitor as they will foul the throttle connection rod if they are on top. I did not use any glue at all. I did however use a further cable tie on the two wires to stabilize as I imagined these wires would vibrate and eventually stress the delicate terminals on the capacitor. I would say this cable tie is very important for durability. Before you begin you will need to refer to #50 on page 3 https://www.arboristsite.com/thread...bosch-electronic-ignition.256095/post-4800770 for original instructions from foggysail. Have fun.

 

[PogoInTheWoods]

Well done, sir. Well done. Thank you for sharing your detailed approach and capacitor information. Your time in doing so will be appreciated by many.

 

[Chazz]

Well done, sir. Well done. Thank you for sharing your detailed approach and capacitor information. Your time in doing so will be appreciated by many.

The pleasure is mine and no problem at all. I am so grateful to you guys for this fix. I feel very lucky I came accross this thread and site so quickly.

 

[Chazz]

Thanks guys. Worked the saw for two and a half hours today and still running great.

 

[KASH]

bump

 

[KASH]

Great job Chazz.I will be trying the Foggysail trick soon can you tell me what you did to connect the white wire in the Bosch electronics.
After you soften and cleaned the potting what wire did you cut and what did you solder your white wire too?
Any help is great.
Kash

 

[PogoInTheWoods]

Any help is great.

Try page 3.

 

[Brufab]

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