It sounds like a good sign if you got a pop out of it.
SUCCESS!!! Just repaired Stihl 045/056 Bosch electronic ignition!!!!!
- Thread starter foggysail
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Bummer. It has to be something simple. How far away from the originally spec'd capacitor recommended by Foggy is the one you are using..., spec-wise, that is. Seems like you were at least getting some sort of activity with the Nova but never zeroed in on the timing adjustment via moving the flywheel and coil around. Considering yours is basically the first case of what has otherwise been a simple and proven fix, seems like if it were a snake it woulda bit ya by now. If the flywheel was replaced by the correct flywheel, the only other variables are the capacitor and your workmanship, not to question the latter after all you've been through, here.
Now my money is on the cap.
powerking
ArboristSite Guru
That is the exact same capacitor that I used on my first fix and it worked great for over a year. I finally got the 045 with the Nova module to start and run but it idles high. If I tune it down to 2,500 rpm it will stall. I had to turn the ignition mount all the way clockwise and then turn the flywheel 1/2 a key width counterclockwise. I also had to lock the throttle wide open with a zip tie and pull really fast. I guess it keeps flooding.
I think I finally figured out the Nova II fix that I was having problems with. At first I couldn't get any pops out of it. Advanced the timing as many have said is necessary for this particular fix and still nothing. Then I treated it like it was flooded. Used a zip tie to give it full throttle and pulled really fast. That would start it.
Today I was trying different flywheel positions and found that I could get it to start between 1/2" advanced and 1 - 1/8" advanced. At 1 - 1/8" it was uncomfortable because the cord would sometimes pull back. It was still hard to start though.
I decided to put in a new spark plug and found that it was a little easier to start but after a while it would be hard to start again. Then I checked the spark plug gap on all the plugs I had tried. They were all slightly wide. I set the proper spark plug gap, turned the flywheel to 7/8" advanced (in the middle of the extremes) and it seems to start and run nicely. Cold start is a little hard but when warmed up it just takes one pull. It also still does not idle well under 2,500 rpm and the chain advances slightly. I ordered a carb kit and clutch springs to see if that will help.
So in other words, try checking your spark plug gap. It should be .020" (.5 mm).
powerking
ArboristSite Guru
.......Advancing your flywheel 7/8"......how did you do that? by removing the key I suppose? I have tried every area in that keyhole slot in the stator plate......I still cant believe my timing could be "that" far off.......I suppose it doesnt take much though.......My spark is so very consistent and strong blue
On mine I turned the plate all the way clockwise and that wasn't enough. Then I removed the flywheel key and marked the crankshaft where the key was in a place where I could see the mark with the flywheel on to adjust it. From the crankshaft, a key width equals about an inch on the circumference of the flywheel. Each fin is about a half inch. Turn the flywheel counterclockwise to advance the timing. I went in increments of 1/8".
I'm surprised you would need to with the foggysail fix. Others have said that with this other fix the 056 saws need to advance about a key width or 1".
If you keep trying 1/8" at a time then eventually the cord will start pulling back. When that happens you know you have gone too far and there may be a different problem if it didn't at least pop before you got there.
I think all the pulling tends to flood the saw. That is why I kept starting it at full throttle.
I'm surprised you would need to with the foggysail fix. Others have said that with this other fix the 056 saws need to advance about a key width or 1".
If you keep trying 1/8" at a time then eventually the cord will start pulling back. When that happens you know you have gone too far and there may be a different problem if it didn't at least pop before you got there.
I think all the pulling tends to flood the saw. That is why I kept starting it at full throttle.
Dumb question--you're just running it w/out a key in the flywheel, then? I wonder if a sudden lurch (chainbrake doesn't apply here, but maybe hitting something?) would slip the flywheel? Maybe there's plenty enough friction between the flywheel & crank that it's a non-issue.
Yes, I did remove the key. I ran it a little doing test cuts and it didn't slip. After I confirm that the ignition is working properly and hopefully won't have to take it off for a long time, I will put some locktite on maybe. I have heard that the key is only for lining up the flywheel and doesn't actually hold it in place.
The flywheel key is for timing alignment. The taper of the crank is where the flywheel gets its attachment strength. A crankshaft will typically break (usually on the PTO side) before a flywheel key will shear.
Other threads address alternative methods and trigger mechanisms and should be referred to for such solutions.
Foggy's fix in this thread (when done per instruction with an appropriate value chip) does not require any timing adjustments and seems to have been successful in every instance but two. Perhaps a review of earlier posts could shed new light on why these cases are failures.
Other threads address alternative methods and trigger mechanisms and should be referred to for such solutions.
Foggy's fix in this thread (when done per instruction with an appropriate value chip) does not require any timing adjustments and seems to have been successful in every instance but two. Perhaps a review of earlier posts could shed new light on why these cases are failures.
powerking
ArboristSite Guru
...I whole-heartidly agree that Foggy's fix is pure genius.....I def am one of the exceptions....Which I believ is "something" in the ignition system.......Im just getting a sore arm pulling this thing 100's of times......
I know what you mean. I just repaired a clone ms381, built an 038 magnum, two 056 magnums and this 045 super. My elbow joints hurt and I also pulled a muscle in my back with this 045.
Before you give up you could try the fix I did on my 045 using the Nova II module. It still starts hard when cold but I'm waiting on a carb rebuild kit to see if that helps, although it started fine with a different ignition. With this fix you know the timing needs to be advanced. Right now there are used Stihl modules on ebay for around $20. They might work better than the Nova module. Part number is 1118 400 1001.
The foggysail fixes I did that were successful were excellent but it didn't work for this ignition on my 045. Now it at least will start and run. I still have to rebuild the carb, put in new clutch springs and put it to work to see how it holds up.
If all else fails I'm considering buying one of those aftermarket ignitions from Germany. I hear they work good and are compatible with these flywheels. Maybe not a bad option for $115.
Any chance these two particular ignitions require additional detail to completely delete the effect of the original cap from the circuit? Heating and scraping potting to cut traces is hardly an exact science. Maybe not the same component or exact same trace in the earlier ignitions? Maybe excessive heat during the potting softening process created additional contact elsewhere in the potting layers not readily evident?
Another 'if all else fails' option is to convert to the equally notorious SEM setup, though it would seem like rustling up other bad Bosch modules for.continuing to implement the Foggy fix would be easy enough and also possibly solve the mystery
Another 'if all else fails' option is to convert to the equally notorious SEM setup, though it would seem like rustling up other bad Bosch modules for.continuing to implement the Foggy fix would be easy enough and also possibly solve the mystery
On the ignition I tried to fix with foggysails method that didn't work, I did the first attempt, then removed all the wiring and replaced with new + used a different spark plug wire. Checked the connection that was cut and scraped more out just to make sure. I pretty much went over everything and used all different wires and capacitor and it was exactly the same.
The spark was not consistent though. It sometimes would spark, sometimes would not, sometimes would start and run fine but would not last.
The other fix uses only the coil and new module. All the other stuff is disconnected.
The spark was not consistent though. It sometimes would spark, sometimes would not, sometimes would start and run fine but would not last.
The other fix uses only the coil and new module. All the other stuff is disconnected.
powerking
ArboristSite Guru
...I would love to find another dead bosch igntion and try the fix again, but no such luck. My spark is always consistent....nice an blue...my guessis, its sparking at the wrong time....Check most prior posts with video
In post 518 you said that you set the flywheel to a position and it snapped the cord out of your hand. I would go back to that position and retard the timing (turn flywheel clockwise) from there at 1/8" increments (from the outer circumference of flywheel) until it no longer pulls back. The cord snapping back is a good reference point that tells you that it is advanced too much.
That should work. I know it sucks when the cord pulls back but the faster you pull the less likely it will pull back. I suggest getting it to a point where the pull back is minimal and if you can't get it to start there then it probably isn't the timing. Be methodical and adjust it in small increments and you will find where the timing should be.
That should work. I know it sucks when the cord pulls back but the faster you pull the less likely it will pull back. I suggest getting it to a point where the pull back is minimal and if you can't get it to start there then it probably isn't the timing. Be methodical and adjust it in small increments and you will find where the timing should be.
I found out why my saw was not starting easily. Nothing to do with the spark plug gap but setting the gap was helpful. The top cover has a piece broken where a screw used to go above the carburetor linkage. Without that screw in, the choke lever was not closing all the way. I fixed it by bending the choke linkage. Starts and runs nicely now.
I also found that the fuel line is leaking due to a loss of elasticity around the fitting. That is probably what was causing a high idle, chain advancing and stalling when turned on its side.
I'm anticipating that after I put a new fuel line in it will be running properly. Just waiting on parts.
After all this, it's looking like the Nova II fix is a good alternative if foggysails method doesn't work. I recommend trying the foggysail method first, then if it doesn't work or it fails later then try the Nova II fix.
I'm pretty sure that between these two fixes the probability of fixing a failed Bosch ignition is very high.
I also found that the fuel line is leaking due to a loss of elasticity around the fitting. That is probably what was causing a high idle, chain advancing and stalling when turned on its side.
I'm anticipating that after I put a new fuel line in it will be running properly. Just waiting on parts.
After all this, it's looking like the Nova II fix is a good alternative if foggysails method doesn't work. I recommend trying the foggysail method first, then if it doesn't work or it fails later then try the Nova II fix.
I'm pretty sure that between these two fixes the probability of fixing a failed Bosch ignition is very high.
Just read about your success in the other thread. Good deal. Should give Powerking some hope!
Would be interesting to see if the Foggy fix would also work for you now that the other issues have been identified. Timing and air/fuel at startup need to be mighty close to designed parameters to work right!
Would be interesting to see if the Foggy fix would also work for you now that the other issues have been identified. Timing and air/fuel at startup need to be mighty close to designed parameters to work right!
Here's a link to using a timing light on a chainsaw. Not the best, but does provide a basic idea and also establishes the presence of an ignition advance on the first coil.
The particular ignition that I just used was originally fixed using foggysails method then I fried it from overheating an 056 magnum + ruined the cylinder. I fried an SEM ignition before the Bosch. Two good ignitions in a row, only two milling cuts made. That problem turned out to be a plugged carb screen due to an aftermarket fuel filter.
The 045 would start and run fine with a different ignition. I don't know why the choke problem only showed with this ignition. On one ignition fix attempt, foggysails method did not work. The spark was inconsistent. I tried the Nova fix but couldn't get it to start. Now that I figured this one out I think I can get it to work. It had good spark.
So far I have had three out of four successes with the foggysail fix. Two of them are in my two 056 magnums and one was fried from overheating and I did the Nova fix and it's in the 045 super now.
The last one, that failed the foggysail fix, I did the Nova fix but still have to put in a saw and try to get it to work. I did try it once already but switched ignitions with a working one when attempts failed.
The 045 would start and run fine with a different ignition. I don't know why the choke problem only showed with this ignition. On one ignition fix attempt, foggysails method did not work. The spark was inconsistent. I tried the Nova fix but couldn't get it to start. Now that I figured this one out I think I can get it to work. It had good spark.
So far I have had three out of four successes with the foggysail fix. Two of them are in my two 056 magnums and one was fried from overheating and I did the Nova fix and it's in the 045 super now.
The last one, that failed the foggysail fix, I did the Nova fix but still have to put in a saw and try to get it to work. I did try it once already but switched ignitions with a working one when attempts failed.
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