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

[PogoInTheWoods]

Your persistence is to be admired, sir!

 

[davidricciardella]

Does anyone have 2 capacitors laying around they'd like to part with?

 

[scallywag]

Does anyone have 2 capacitors laying around they'd like to part with?

If you get real stuck and can't find any in the US?.... I have a few spares!

 

[Ty Stanton]

Hi there. I just found this info last night and I would love to save my 056 super. I found this on Ebay and was wondering if it is the correct part. If anyone inthe US has Aextra one they could sellmeit would be appreciated. http://www.ebay.com/itm/2pcs-PHILIP...e371105&pid=100005&rk=3&rkt=6&sd=161203941323

 

[tntatro]

Hi there. I just found this info last night and I would love to save my 056 super. I found this on Ebay and was wondering if it is the correct part. If anyone inthe US has Aextra one they could sellmeit would be appreciated. http://www.ebay.com/itm/2pcs-PHILIPS-BC-MKP378-1uF-400V-5-P-27-5mm-Film-Capacitor-222237852105/151241678480?_trksid=p2047675.c100005.m1851&_trkparms=aid=222007&algo=SIC.MBE&ao=1&asc=20131003132420&meid=5cbf31a813674a34bca011f1ae371105&pid=100005&rk=3&rkt=6&sd=161203941323

That is almost identical to what I have been using except mine says MKP379 instead of MKP378. Everything else is the same. If I remember right I believe it's the 1uF and 400V that is important. I also used the 630V and it worked. I'm pretty sure you got the right one.

 

[Ty Stanton]

Thank you. I have ordered them. I'll update in A month when they come.

 

[johndean]

Hi,
I am the seller on eBay who had the capacitors you guys were using but I've run out of them. I do have many other caps available but you said they should be pulse rated and that limits things a bit. If you can provide me with more info about the ratings for the caps you need, I can try to get some for you, maybe some much closer to the original or even superior to the original. Unfortunately, .8uF is not a common capacitance at all but I'm sure I can get .68uF, if they will work. The voltage could be difficult. How important is the 400 volt rating? Will 250 volt caps work? Also, is physical size a factor? I believe you said that the ones I was selling on eBay were a bit larger than the original. Finally, do they have to be polypropylene or will polyester caps work?

Hi All,
Thanks for all the info on this repair. I was able to source 2 1uf 400v rating on Ebay . They were rectangle type but by removing part of the board was able to mount them vertical in the space where the original one wentl.
It now works well. johndean australia

 

[Dostin]

Bill--

The only thing I ask is to keep the forum informed of your progress so ALL can benefit. Today we are still waiting for Dostin's status with his problem. His last post, 402 leaves the board hanging after my suggestions. To my knowledge his is the only mod that supposedly failed even though he indicates that a high voltage was present when he received a shock. But if his saw has no spark...........

Good luck and enjoy

Sorry for the wait but Life took over and the saw sat in the basement until today. I still have no spark but maybe found the culprit....seems I overlooked the specs on the capacitor I got in the mail and this could be my problem. The Capacitor I have on the saw is : .1uF 5% 1000volts, Vishay Film Capacitor, RoHS compliant from Mouser. I did confirm that I have continuity all the way through the transformer and spark plug wire. I also confirmed that I get some voltage at the capacitor when I spin the motor with a drill and the other side of the capacitor has a good ground. So I will be ordering a new capacitor and we'll see what happens!

 

[powerking]

So for those of you that have been following my posts, I have done the FoggySail fix on my Bosch setup, I did end up getting spark, but I could not get that thing to run at all. I had great blue spark and great fuel. I ended up coming across another Bosch ignition (unmodified). I installed it and low and behold it fired on 2nd pull and ran great!!! I wonder if something in the trigger portion of the coil is bad or out of time somehow, but for now, I will run it with the unmodified Bosch setup and see how well it goes....

 

[tntatro]

Your suspicions were right all along. Glad you got it going.

I got my second Nova II/Bosch ignition going and it runs good. I think I had so much trouble the first time around because the carburetors are a bit old and they would do okay with the idle at 2,500 but not so good with the Nova fix that requires them to idle at 2,000. A good carb cleaning and diaphragm soaking fixed that. So far all my Bosch electronic ignitions for the 056 have been successfully repaired. Some with the Foggysail fix and two required the Nova II fix.

I wonder if yours has a bad coil or if it is the trigger. If it is the trigger then the Nova fix should work but if it's the coil then it's probably done. I have two more untested Bosch electronic ignitions to mess with and another that has spark but haven't run it hot yet. I also picked up an early style SEM. So far the SEM has nothing at all.

 

[powerking]

Your suspicions were right all along. Glad you got it going.

I got my second Nova II/Bosch ignition going and it runs good. I think I had so much trouble the first time around because the carburetors are a bit old and they would do okay with the idle at 2,500 but not so good with the Nova fix that requires them to idle at 2,000. A good carb cleaning and diaphragm soaking fixed that. So far all my Bosch electronic ignitions for the 056 have been successfully repaired. Some with the Foggysail fix and two required the Nova II fix.

I wonder if yours has a bad coil or if it is the trigger. If it is the trigger then the Nova fix should work but if it's the coil then it's probably done. I have two more untested Bosch electronic ignitions to mess with and another that has spark but haven't run it hot yet. I also picked up an early style SEM. So far the SEM has nothing at all.

Im in the process of softening up all the "potting" on the old bad bosch unit to see if something visibly doesnt look right. I was always getting spark, but maybe it was 180 degrees out of phase or something.........Now its time to get a nice bar and chain and try her out!

 

[William Balaska]

So for those of you that have been following my posts, I have done the FoggySail fix on my Bosch setup, I did end up getting spark, but I could not get that thing to run at all. I had great blue spark and great fuel. I ended up coming across another Bosch ignition (unmodified). I installed it and low and behold it fired on 2nd pull and ran great!!! I wonder if something in the trigger portion of the coil is bad or out of time somehow, but for now, I will run it with the unmodified Bosch setup and see how well it goes....

Out of time, the other issue with these modules.

 

[powerking]

Out of time, the other issue with these modules.

....This wasnt a Nova Module...This was done Foggysail Fix.....by moveing the internal cap and making it an external cap for heat transfer I believe

 

[powerking]

.....For those inquiring minds about the inside of the Bosch Ignition........see pic..........Also the blue thing is the cap that goes bad.....VERY cheaply made...actual value is .8uf/400volts

 

[mgr]

Are there other markings on the cap?

 

[powerking]

 

[globtrotter69]

Hi.I'am a owner a Stihl 056, and I have the same problem with ignition, my question :do I have to cut the connection on the red line that was correct?? or no?.

 

[mgr]

Yes, you have to cute it. That connection is the faulty cap.

 

[powerking]

I went out and ran the saw hard yesterday morning and it died after about 15 minutes with no spark. SO I took this coil out and did the Foggysail fix to this coil and low and behold, This one was a success!! I ran the saw for about an hour after that and it didnt miss a beat!

 

[Alex2506]

THE FIX!!!!

This may be a little verbose but my intent is to convey all that is needed to implement the fix. So first, I will start with a failed ignition showing and describing the repair steps. The tools you will need are: soldering iron....25 watts should work using solder designed for electronic work NOT PLUMBING SOLDER, I recommend an inexpensive heat gun...Harbor Freight maybe but with care you can work without one, epoxy designed for plastics.... HD or Lowes for about $5, electric drill with a 1/4 or so bit, a wire crimp tool with a lug (see pictures), and last I used a hot glue gun to sort of seal up the mounted new capacitor. The hot glue I used is industrial quality and you can get by substituting caulking selected from one of the many types available. And of course both a blade and Philips screwdriver will come in handy.View attachment 348005

Heat the small section as shown in the above picture, try to avoid heating the pulse transformer. The potting does not have to melt, just soften so a small section can be removed with a screwdriver or other suitable tool.
View attachment 348006

DON'T GET CARRIED AWAY chipping out that potting material! Take you time doing this. In teh above picture you see the shinny tinned copper PC run. The next picture will show where I want you to cut. Try to leave about 1/8" gap.
View attachment 348005 View attachment 348006 View attachment 348007

Heat up your soldering iron and get ready to solder an insulated wire onto the right hand side of the exposed PC bus (not the short piece to the left). I salvaged my wire from an old computer power supply and because I added 3 wires, I used two different colors so I could tell which went where. 18 gauge stranded wire will work fine. Please! Don't use a length of solid core house wire, your asking for trouble.View attachment 348009

I tucked that yellow wire under the pulse transformer. There is another wire that you add using a crimped lug. Secure it under the screw (holding the pulse transformer) above where you made your cut. Don't tighten the screw yet. Later when you install the ignition that lug will be in the way trying to get the mounting screw into the saw proper. That is when you will tighten the lug down. OH-- avoid using the yellow sized lugs. They are much larger and can get in the way of the rotating flywheel. Adding a third wire is entirely up to you, I used black so I would not mix it with the others. I cut the shutdown wire that goes to the on/off switch and replaced it with this third wire. If you don't bother replacing the shutdown wire, take care that the old wire's insulation is intact, cover it, tape it or just cut it out, it your decision. Remember if you disable that wire, you disable the on/off circuit to shut the saw off.View attachment 348012

Now here is where each of you can add value! I squeezed all three wires into the shared hole with the spark plug wire. There is a rubber grommet in the hole so they can be made to fit. Maybe you want to drill a new hole....???? Anyway, that is left for you to decide. After pushing the wires into the grommet, I used a piece of steel wire... coat hanger will work... shaped with a hook on the end to fish the wires out. Next I drilled 3 holes in the plastic air shield....1/4" or thereaboiut should work. Tow of the holes is for a tie wrap that I used to hold the new capacitor in place. The other hole is for the two yellow wires to pass through. Note I left the wires on the outside of the plastic to avoid them getting caught with the flywheel's fan. That's why you need to drill a hole for the wires.

View attachment 348013

Scrub the plastic under the tie wrap with alcohol and also scrub the new capacitor with the same. Mix up your epoxy. Paint generous amount of epoxy across the section under the tie wrap and on one side of the new capacitor. The capacitor will seat under the tie wrap with its two wire terminals pointing downward toward the flywheel. MAKE SURE you seat that cap such that it has space for the wires to be soldered to the terminals such that they don't get damaged by the fan. That is important! After pushing the new cap into place, tighten up on the tie wrap. Next pull both yellow wires into place and cut them leaving enough length to strip 1/4" or so needed to solder one wire to each terminal.

View attachment 348022

I used my trusty old, beat up glue gun to bury the new capacitor along with the new wires with hot glue. This ensures they will not move about with the saw's vibration.


View attachment 348016


View attachment 348021


IF YOU GOT THIS FAR---------- YOU HAVE COMPLETED THE FIX!!!!!!!!!!

You can test the fix after the epoxy dries along with the hot glue or caulking or whatever you select to use.

Assemble the saw so you can pull the starter rope....remove the spark plug from the engine, clip a grounding wire to it and pull the starting rope. If things go well, you should have a nice blue spark!

Will try to answer any questions-- Good luck, you can do it! Its not brain surgery!

Foggy

Hi, thanks for info.. I have a question, you said you added 3 wires, 2 yellow and 1 black, where did you conected the black wire?
Thanks!