Remember-- "me no mechanic?" The guy I purchased the saw from 2-3 years ago said he had modified the cylinder. I don't follow this stuff closely enough nor know enough about the mechanics to give advice. If I needed greater saw power, I would purchase a different model without trying to re-engineer something that works. JMHO
SUCCESS!!! Just repaired Stihl 045/056 Bosch electronic ignition!!!!!
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Remember-- "me no mechanic?" The guy I purchased the saw from 2-3 years ago said he had modified the cylinder. I don't follow this stuff closely enough nor know enough about the mechanics to give advice. If I needed greater saw power, I would purchase a different model without trying to re-engineer something that works. JMHO
I have a question about replacing the switch. Will this switch work? Do I cut the end off the old wire and solder it onto the new switch and add a ground? There appears to be some type of ground wire but it wasn't attached to the old switch. It is held on by screws in two different places (second picture). I don't know what part actually failed so I thought I should try the switch first. The old switch wire appears to be in good condition.
The switch in your pictures appears to be a single pole, double throw and if so, it should work. You really should use an ohm meter or continuity meter to determine which posts to connect your wires to. A single pole... think of this as a toggle where it makes contact between one of the other two contacts. When the switch is toggled, the contact is moved to the opposite terminal contact. If you screw the wiring up by wiring to the two contacts instead of between the pole and a contact it will not work.
The purpose of the switch is to connect the wire from the ignition proper to ground thereby stopping spark to the plug. It does not matter if the ground is connected to the pole or a contact as long as the ignition connects to matching pole or contact.
Whether this switch will work of course depends on using a working ignition or one that is modified as described in this thread. Good luck and remember this is not rocket science.
Foggy
The purpose of the switch is to connect the wire from the ignition proper to ground thereby stopping spark to the plug. It does not matter if the ground is connected to the pole or a contact as long as the ignition connects to matching pole or contact.
Whether this switch will work of course depends on using a working ignition or one that is modified as described in this thread. Good luck and remember this is not rocket science.
Foggy
I decided to go ahead and modify the ignition since it is all taken apart already. I don't have any 18 gauge stranded wire. I just went to Lowes and all they had for 18 gauge was solid. I have 14 gauge stranded, a wire that went to a charger for an old rechargeable power screwdriver (pretty small looking), 18 gauge solid and maybe some 16 gauge speaker wire. I'm sure if I look around I can find more. Do you recommend the 18 gauge stranded or can I go bigger or smaller?
I now know what you mean about the cheap switch wire. I must have let the piece flop around too much and pulled apart the insulation.
I now know what you mean about the cheap switch wire. I must have let the piece flop around too much and pulled apart the insulation.
NO! You do not want to use larger wire, too tough to work with.
#20 stranded will work although it is not as robust as 18. Try Radio Shack if there is one available in your neighborhood. The Company closed many stores but not all.
Crude but lamp cord will work
Yes--
I got my saw together and it starts and runs good. I replaced the switch and switch wire and used the 1uF 630V 5% pitch P:27.5mm capacitor. I only started it and let it idle for a minute. I was a little worried because I did a terrible job soldering but the connections are there. I will mill with it next weekend and maybe a little during the week and keep you posted on results.
CONGRATS!!!!
Encouraging to read about successful modifications. By the way and for others--- there is nothing wrong using the higher 600 voltage capacitor I recommended over the 400 other than it is slightly larger.
I didn't end up using the power cord wire. I found some more wire that appeared to be the same gauge but the insulation was thinner and tougher than the cord wire. I don't think I could have got 3 cord wires through the grommet because they looked too thick and flexible. I'm glad I replaced the switch wire, when I pulled it out of the grommet all the insulation easily stripped off and the wire wasn't even connected well. It pulled apart where someone had spliced it in the past.
Well i have to say i did up my bosch ignition as described and i get a nice blue spark. But it will only start and run for about 3 seconds...checked and still have nice spark...but this intermittent thing is a PITA. I used the correct capacitor and all the solder joints are heat shrinked...not sure what to do....im 99.9% sure its not a fuel issue and its got a brand new plug. Not sure where to go from here.
I purchased a second saw that was claimed to be "running fine" because the other one I own had/has some mechanical issues. Anyway, the so called "running fine" was not and I did get some money returned because it had the typical ignition issues this thread discusses. So I did the upgrade!
My saw ran for a few minutes and pooped! Yeah, the first thing I checked was the spark and like yours, I had a healthy blue arc. My problem was the air filter on the carburetor. After cleaning it the saw runs just fine. Note-- the original problem was ignition, not the air filter. Make sure your's is clean.
Also I presume you either replaced or removed the original shut down wire, the one that goes to the switch.
My saw ran for a few minutes and pooped! Yeah, the first thing I checked was the spark and like yours, I had a healthy blue arc. My problem was the air filter on the carburetor. After cleaning it the saw runs just fine. Note-- the original problem was ignition, not the air filter. Make sure your's is clean.
Also I presume you either replaced or removed the original shut down wire, the one that goes to the switch.
I am running it with no filter while its apart...new kill wire soldered after i dug out a little epoxy and it got double heat shrinked. And the end of the kill wire has a wire nut on it. And i have been completely through the carb and it is very clean and all rubber diaphragms are nice and pliable. I have also tried dumping fuel down the throat of the carb and it just fires when it wants to but only will run for a few seconds.
I guess and I do mean guess it could be ignition such as arcing with the spark plug wire. Could even be that the spark plug wire is not properly mated with the ignition coil. Your mod looks fine other than I would have filled the void you needed to make in the potting material.
Maybe others will join in with suggestions--
Maybe others will join in with suggestions--
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