Stihl 041 AV Electronic - No spark

[bgsengine]

Got a NOS coil a few days ago and finally had a chance to play with this thing again today. Still no spart with the new coil. So now I'm faced with either trying to source a new Stator, or convert the whole deal to points. Questions:

Anyone have a good source for a new stator?

ebay is the only place I know - I also saw on there where some guy is selling a whole stator plate that is the points ignition stator converted to electronic module already..

Alternatively, I've never replaced a points ignition with one of those Nova modules before. How complicated would it be to convert this saw to one of those setups?

Snip, Snip, Screw, Screw, Walaa! - in other words, not complicated

There are a couple points-type flywheels on ebay and are cheap enough. What is involved in the conversion?

As I mentioned in prior post you may still need stator , or you will need points stator with coil - on your machine, I do believe the stator is the "primary" side of the coil, and the "coil" that is mounted to the outside is just the secondary - so new coil wont fire if primary coil (part of stator plate) is bad. So.... if you want to go to a new stator such as points ignition you likely also need new flywheel (may have magnets in different position in relation to keyway) as well as stator plate, points, coil, wiring, etc..

Maybe a better question is: can anyone point me towards what module to use and an instruction manual? Atom seems to be another brand of the same sort of deal. I just can't figure out (without seeing, I'm hoping) how on earth you can time the saw with a module mounted externally…?

- Most of the modules including the Oregon 33-053 Nova module have instruction sheet included - they can fire on a "leading" or "trailing" basis (polarity reversible) so one module covers a lot more.

Timing is achieved by the electronic module switching based on the primary electrical current being induced by the flywheel - It detects when the current begins to increase (as the flywheel magnets come closer to the coil windings, the current/voltage being induced gets stronger the closer the magnetic field is to the windings) - which switches it "on" (I.E. Points close to create current flow) and then detects when the voltage begins to drop again (as magnets move away from coil windings) and switches it "open" just like points firing - timing is controlled by the flywheel key just like with points ignition and by the sensitivity and programming of the electronic module - most are programmed to fire at about 25 degrees BTDC or so, or right about where a .015 - .020 point gap outta put it.

[JonCraig]

Timing is achieved by the electronic module switching based on the primary electrical current being induced by the flywheel - It detects when the current begins to increase (as the flywheel magnets come closer to the coil windings, the current/voltage being induced gets stronger the closer the magnetic field is to the windings) - which switches it "on" (I.E. Points close to create current flow) and then detects when the voltage begins to drop again (as magnets move away from coil windings) and switches it "open" just like points firing - timing is controlled by the flywheel key just like with points ignition and by the sensitivity and programming of the electronic module - most are programmed to fire at about 25 degrees BTDC or so, or right about where a .015 - .020 point gap outta put it.

That makes a lot of sense--thank you!

So to convert this to a Nova module, I'd need the points-type flywheel, points-type stator, points-type coil, and the replacement module.

Then (making sure I understand…) The module gets wired between the stator and the coil. This sounds do-able. Am I missing anything obvious?

Thanks again for all your help! My Father In Law is the owner of this saw, and has recently had a heart attack that's made him unable to use lots of his tools. When he saw that I had an interest in getting it running again, he's suddenly very interested in it again. It was his first Stihl, and I think giving it back to him all fixed up would do a lot to help his spirits. Especially if I were to use it to help him get this winter's firewood in. Anyway… thank you again for your help in making this happen!

--JC

[JonCraig]

Works like a champ now. Thanks again to all who helped! My father-in-law was thrilled to hear his 041 thumping again.

[bgsengine]

Works like a champ now. Thanks again to all who helped! My father-in-law was thrilled to hear his 041 thumping again.

Excellent! So, what all did it take to get 'er fixed up?

[JonCraig]

You're gonna point & laugh at this newbie. When I tried out the new coil, I used a drill to turn the flywheel to check for spark. And guess who was spinning the drill the wrong way? The other day I tried again, realized I was stupid, flipped the reverse switch on the drill, and she sparked like a champ. New coil was all I needed all along.

[bgsengine]

Ahh yes.. Some engines just don't want to run backwards..

Always better to test things like that with the actual recoil starter as well -Also Drill can damage the flywheel nut (Overtorque and break it off one way, or loosen it and get a sheared key going the other way, as well as messing up the hex and making it harder to remove) and spinning by hand, does not get enough RPM to create a consistent spark.

Plus, if you happen to "forget" you have something stuck in the spark plug hole or one of the ports to block the piston while working on it, well.. you get the idea..

But, you would not be the first person to make that mistake - I've seen even seasoned professionals trip themselves up by something so simple.

Put another way: "Pobody's Nerfect"

[JonCraig]

All good points, yessir. I won't even mention the little bits of nylon rope that i pulled out of the combustion chamber with tweezers. I own a piston stop now.