Stihl 056 bosch ignition

[trappermike]

The magneto didn't fail the aftermarket triggers did,on magnetos with a "full magnet" flywheel. But maybe now the newer trigger modules are better and they won't fail in those apps. I used the jobber trigger in a lot of different motors and they worked great,I hope they work now in the 056. I used the Stihl module too with good success.

 

[dieselpilot]

If you get a chance, final configuration pictures would be much appreciated!!!

 

[foggysail]

Very interesting thread! There are things I don't understand though. For example what problem is being solved, the high voltage coil opening up or the control module. Adding a trigger unit just replaces the control circuitry and has ziltch to do with the high voltage transformer heating problem. Next, I don't know how those trigger modules function. Those in the Bosch ignition use a separate coil from the high voltage circuit to provide the stored energy that gets dumped by the thyristor into the high voltage transformer. But if it works ... it works. You cannot ******** physics. OH and EBay sells those trigger units now for big bucks... over $50 each.

Obviously I share the same woos with my Bosch ignition used in my 056. I just took a chance and ordered the high voltage transformer for a TS350 (thanks to getting info here in the forums) and intend to give it a try. If the mechanics are different than what I now have, well then it will not work. But for $30 delivered from EBay I thought it is worth a shot.

General comment! Electronic designs for circuits such as those Bosch used in the 056 and others should have had a better reliability analysis before they were implemented into chainsaws. There is no black magic here but there is poor electrical engineering that all owners of those early saw designs now suffer with while trying to keep an old work horse functioning.

Foggy

 

[foggysail]

A follow up to my post above. I ripped apart my 056 ignition's control section this afternoon. I do not think the fault with these things is related to the magnetics because I found the charging capacitor in this jewel of mine SHORTED! The value is 0.8 microfarad rated at 400 V. Tough to get at, had to remove all the potting material. This is the capacitor that stores the energy to transfer to the high voltage transformer via an SCR (thyristor). But it looks like the ignition system can also work as a magneto as others are successfully getting it to work with just a trigger module.

This would explain why others have had such great results changing just the control circuit. So today I ordered a Kawasaki 31-9334 which cost about $20 including shipping. I would reassemble the ignition I ripped apart to test it but I don't have many capacitors in my collection. If I find one before I build in the Kawasaki, I will give it a try. I am NOT going to mount it inside the existing ignition but rather somewhere where it is cooler and just run wires back to the transformer under the flywheel.

Back to today's find, the capacitor's physical size is interesting. It resembles a half drum sliced vertically with that length around an inch. It is about 075" wide and about 5/8" high. What makes these dimensions interesting is they are VERY small for the capacitance value while rated at 400 V. One way that can be done is to make it with a mylar dielectric. But if it is made using mylar, there is a major shortcoming at least for this particular application. Metal film Mylar that I have seen are only rated for 85 degrees C (185 degrees F). The control module is in a very hot environment so my guess is this part is the culprit and not the coils. But remember, I am sampling a quantity of one.

Just thought I would share what I found.

Foggy

 

[DIYDoug]

I'm bought some capacitors to fix my ignition module. Somewhere I came across these, which are 400v, 0.82 uF. Other links point to a 1.0 uF. Will this .82uF work?
http://www.ebay.com/itm/310579397823

 

[Rx7man]

They're more money ($7 each) than the Ebay ones, (perhaps better quality?), and you can get them in different ratings... just thought I'd post of another place you can source them
http://ca.mouser.com/ProductDetail/...=sGAEpiMZZMv1cc3ydrPrF6b39BhxIu4vTPelFB1kQag=

 

[POC]

Should this work for a 056 Av Electronic?

Sent from my SAMSUNG-SM-G870A using Tapatalk

 

[foggysail]

Should this work for a 056 Av Electronic?

Sent from my SAMSUNG-SM-G870A using Tapatalk

It will work if it's the same ignition that I analyzed and provided repair instructions. Please see:

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

http://www.arboristsite.com/communi...ihl-045-056-bosch-electronic-ignition.256095/

 

[POC]

It will work if it's the same ignition that I analyzed and provided repair instructions. Please see:

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

http://www.arboristsite.com/communi...ihl-045-056-bosch-electronic-ignition.256095/

I've found that in the mean time, thanks.

Sent from my SAMSUNG-SM-G870A using Tapatalk

 

[foggysail]

I've found that in the mean time, thanks.

Sent from my SAMSUNG-SM-G870A using Tapatalk

Good luck!!! Remember it's not rocket science, others have implemented it with good success with no electronic background and you will be able to also..

 

[yellowhair]

I just traded for a good looking 056 av super and found no spark. I was reading this link (googled and found same) before joining and found it most interesting - thus the reason that I joined. I don't know much about these older Stihl saws, but I do work on a lot of the smaller saws - everything from Stihl to Poulans - I'm retired and find the work relaxing and informative. Anyway, when I took the flywheel off the saw I found a Bosch magneto stamped as such with Stihl number 0204 098 006, underneath the flywheel and magneto package is what I believe to be an SEM ignition (it has the name Selettra stamped on the underside) with the number 1108 400 0804 A. I have read some discussions about 3 types of ignition packages but find it hard to believe that these two would be intermixed. Does it appear to you, as to me, that someone has mismatched the parts? Thanks for any input.

 

[trappermike]

So did you actually affirm how mant degrees before TDC is it firing now?

 

[trappermike]

We tried those in the 80's but they died or fired way out of time. Put a timing light on it and see...

 

[trappermike]

They work great with most ignitions but I'm not sure of 056.

 

[trappermike]

Well at the time we did it with a guys falling saw and it came back in a week dead. The guy had a stuttering problem and called the mechanic a c-c-c-**********,he was mad,so we stuck an original ignition back in it. Then the next one died,I had to traval a 100 miles in arctic winter to some tiny place,I just stuck a new one and went ..
I'm not convinced these trick little units work on a system with magnets all around the flywheel.

 

[trappermike]

They seem to work great on other ordinary ignitions,specially where the magnet is in one place on the flywheel. My next antique hotsaw has one...

 

[nolids]

Just joined up to share my Sachs Dolmar 133 story. I got the free saw complete and it looked hardly used. After rebuilding the carb I could get it to start, but only run for a few seconds. Then it would not start unless I waited 24hrs. So this went on quite a few times with me thinking it was the rebuilt carb not adjusted right. Then one morning I got it to start, and actually stay running at high throttle for maybe a minute while cutting a log. Then it slowly lost power and died. No start.
I finally figured out it had to be the ignition. So I started swapping coils and that didn't work so I figured it must be the module. A Nova2 didn't help, and I had the hardest module to find-- a SEM GE! No replacement to be found. This is 2018 and parts are getting harder to find than when this topic was started years ago.
I had been reading the chainsaw boards and found the link for the German complete module and coil that said it was for a Dolmar 133. Great! I also found a Bosch flywheel to go with it. So after waiting a couple of weeks I got the parts and put them in. I checked the timing with a timing gun and it was something like 32 degrees AFTER top dead center. I figured that the Sachs Dolmar 133 and the Dolmar 133 ignitions had to be different.
Now what? I decided to drill new adjusting holes in the backing plate. One of them had to be right next to the coil. That took it to just after TDC. I needed 26 degrees BTDC. So I used the top mounting screw that held the coil on and tapped it out to the same threads as the hole for the mounting plate and it was aligned perfect for a longer screw that held the top of the coil to the base plate and moved the base plate counter-clock wise screwed down.
Guess what? I checked timing and it was now 26 degrees BTDC and the chainsaw started with a roar with just one pull! That was at quiting time last night so I'll see what happens today. I can never tell, this saga has been going on for months.

 

[Rx7man]

Another option would be to run the flywheel keyless and advance it... I found the trick to that is to make a mark on the flywheel approximately where it fires in relation to the coil (or case, if you have a coil that's under the flywheel), then, run it with a timing light and mark the case where it lines up with the mark on the flywheel. After that, remove the key, move piston to desired firing position and retighten the flywheel... Might be handy in other cases, glad you got it to work though!

 

[nolids]

Another option would be to run the flywheel keyless and advance it... I found the trick to that is to make a mark on the flywheel approximately where it fires in relation to the coil (or case, if you have a coil that's under the flywheel), then, run it with a timing light and mark the case where it lines up with the mark on the flywheel. After that, remove the key, move piston to desired firing position and retighten the flywheel... Might be handy in other cases, glad you got it to work though!

I tried changing the flywheel position and it didn't change the timing. Then I realized that only works with an outside coil. I am getting great spark now, but the carb isn't working quite right so keeping it running when cold is a trick.

 

[hotshot]

I tried changing the flywheel position and it didn't change the timing.

What? It has to change the static timing.

It makes no difference if the stator sets inside the flywheel/rotor, or outside. Moving the stator in the direction of flywheel (FW) rotation ******* it, opposite the FW rotation advances.

Saw engines rotate CCW on the FW side (most do...)

So just the opposite, rotating a keyless FW CCW on the shaft taper advances the timing.

Are you using an old school timing light, a 12vdc battery, and a paper timing wheel for your timing check?