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

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Be happy to. Will also attempt to approach it as a vehicle to gather info from the masses in broadening the spectrum of saws that could benefit from the fix. Need to think on it a bit. I obviously tend to get rather wordy and will need to keep it to the point!

I presume some of your material here would be cool to duplicate in a consolidation effort..., hopefully with your blessing in the new thread? Not sure how much would even be necessary to make the point that it's simple and works..., just in a brand agnostic approach.
 
Be happy to. Will also attempt to approach it as a vehicle to gather info from the masses in broadening the spectrum of saws that could benefit from the fix. Need to think on it a bit. I obviously tend to get rather wordy and will need to keep it to the point!

I presume some of your material here would be cool to duplicate in a consolidation effort..., hopefully with your blessing in the new thread? Not sure how much would even be necessary to make the point that it's simple and works..., just in a brand agnostic approach.


Poge-- I fully support everything that will help make life easier for others!!!
 
In doing some additional searching/reading on the subject, it seems as though the same approach has been somewhat successful before using the OEM Stihl trigger unit, but with timing issues. Without re-reading this whole thread, I didn't recall seeing any reference to timing problems using the method detailed here and am assuming my recollection is correct?
 
Foggy,

As this seems to be a re heated hot thread for a while until these old things finally croak, it draws questions as to other makes using this Bosch unit, I'm a prime example. Perhaps another approach to the subject as opposed to starting another thread with links etc.
Consider asking the mods to re title the thread to something like Repairing the 1980's Bosch SS ignition on Stihl, Husky, Dolmar etc.

Just my 2 cents and thanks again.
 
Foggy and you just gitter done!

Wrong place to post but is it my old XP box or the site, but I'm having hella time with the site.
Page loadings take forever like often a minute and sometimes will time out. I'll make a post and often it won't go through.
 
Nope. Spinning it with the drill shows the same advance start point and full advance mark as with the oem capacitor. Bear in mind that the drill only turns 1650 max so I have no idea what will happen above that. But the curve flattens out long before 1650. *Note that I haven't run the saw yet, only spun it up to check timing by motoring it.
 
Foggysail YOU ROCK! I got my cap in today and wired and soldered it in. got myself a nice blue spark! Primed her with a quick squirt and she fired off! Now to wait for my rebuild kit for the carb and I should be good! THANKS!
 

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Foggysail YOU ROCK! I got my cap in today and wired and soldered it in. got myself a nice blue spark! Primed her with a quick squirt and she fired off! Now to wait for my rebuild kit for the carb and I should be good! THANKS!


SO an update, I rebuilt the carb...no start....pulled the plug and put my tester in, see spark in the window, but no spark on actual plug....Tried 4 different plugs....no spark. But I do get spark with the tester...maybe just not strong enough? Maybe I got a bad Cap? I did use a 630volt cap, versus the 400V that was in the tutorial...maybe that is the issue?
 
...Here is my vid clip that I took...sounds like others have had issue with bad cap maybe? I do have 2 coming from Japan..should be here within a week or so......
 
Is the air gap set correctly? And do you have a good connection to ground when just testing with the plug itself? Doesn't seem like the model plate would suffice. And the plug lead is good otherwise.... Sorry. Just thinkin' out loud....

It'll be interesting to see what you come up with. Thanks for sharing, and good luck with it..
 
There is a ground strap that goes on the screw that holds that air flow cover that he put the thingamajiggy on and the tank. This grounds the handle system while being isolated by the AV mounts. It also allows the kill switch to ground out. If that strap was broken or left off the plug would not be grounded when checking. I always hold it wherever I can and it sparks, grounding right through the paint.
 
....Stupid me...When I made that vid, I should have also said that I had tried grounding the plug right above the cylinder as well!Sorry about that.... Today I tried to see if Igot spark again from the plug. I got very weak spark from the plug, but only on the first pull of the rope, other yanks on the rope yielded nothing....My "guess" at this poin would be that something is wrong with my cap....maybe it sat on shelf for a long time......At this point I will wait for my other caps to arrive and give them a shot.....Oddly enough the igntion system has just enough juice to light the spark tester, but not sufficiently fire the plug....
 
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 Foggy,
I'm the guy who was selling the 1uF 400 volt polypropylene capacitors on eBay. I sold out a long time ago but still get a lot of requests for them, along with questions about repairing their chain saws. Unfortunately, I haven't been able to locate any more of those caps for a reasonable price. Those caps were also rated for AC and Pulse applications, which made them particularly well suited for this application. I do have some 1uF 400 volt Arcotronic polyester capacitors that should work but they are not rated AC and pulse but are rated 105 degrees C. and are specified for automotive applications. Also, I do have some 1uF 250V polypropylene capacitors and would like to know if caps rated for only 250 volts will work to repair these ignitions??? From what I understand, the circuit uses this cap to store a charge that is then dumped into a high voltage transformer. What I don't know is the voltage level that is being stored.
Finally, I seem to remember reading that the original cap was actually .82uF at 400 volts. If they are being used to store a charge that is then dumped into a transformer, it would appear that larger capacitance would work as well, if not better.
If you can respond and let me know if any of this makes sense to you, I would really appreciate it. I would love to be able to answer some of these questions I get from people trying to repair their chain saws. Thanks! Paul
 
....Stupid me...When I made that vid, I should have also said that I had tried grounding the plug right above the cylinder as well!Sorry about that.... Today I tried to see if Igot spark again from the plug. I got very weak spark from the plug, but only on the first pull of the rope, other yanks on the rope yielded nothing....My "guess" at this poin would be that something is wrong with my cap....maybe it sat on shelf for a long time......At this point I will wait for my other caps to arrive and give them a shot.....Oddly enough the igntion system has just enough juice to light the spark tester, but not sufficiently fire the plug....


....So the new caps came today and I was anxious to get out and try them....I soldered in a new cap and tried it out....got great spark across the spark tester, but no spark at the plug!!!! I have tried 4 different plugs, I have also used the original plug from that saw in another machine and it works there. For some reason, there is not enough energy in the ignition system to jump the spark plug gap, but enough to fire the bulb in the spark tester.........In the attached pic, the new cap is on the right, and the old one I took out is on the left........open to any suggestions at this point. I REALLY want to see this 056 Super work, but its not looking good. Im pretty sure there is no air gap adjustment on the bosch coils.....
 

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I wonder if you have insulation on the kill wire that is grounding out the ignition. When I remove the coils-stator plates the insulation 9 out of 10 times is bad and falling off somewhere. I loosen up the coil and put heat shrink tubing all the way from the end prong through the back of the stator right to the top of the coil where it goes in. Then I hit the top with some liquid elec tape to seal the joint. Half of the saws I get have no spark or weak spark because this kill wire is grounding out.
 
I re-did the wiring all the way from the potting, up to the switch, I will take the flywheel off again and check things over....maybe my wire routing........
 

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