Stihl 041 Super AVE - No Spark - SEM Electronic Ignition

[vision976]

Yes, on the time and money ahead thought. The Sagenspezi electronic ignition has the "Nova ii" ignition module (or whatever brand they use) on the stator plate, which means it gets installed under the flywheel, so the electronic module gets subjected to high heat. Probably not a good thing, but since they've been selling those units for a long time, they must obtain satisfactory service from them.

I bought an 041 parts saw off of fleabay this morning; the pictures show it to be an AV electronic model, so perhaps it has the Bosch electronic ignition module/flywheel. Ostensibly it doesn't run, but the cause was not noted. When I receive it, I'll see whats under the flywheel (and if I can make it run without doing anything to the ignition)

There is a thread over on another forum where the author modified a Dolmar 133 saw's Bosch electronic ignition module to use the Nova ii chip. He had to rotate the flywheel from its normal position to properly time the spark. The Bosch unit in his pictures appears to be exactly the same one that was used on the 041, 045 and 056 Stihl chainsaws.

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[av8or3]

Just sayin, you can still prolly score a complete points/condenser magneto setup for around $100. I don’t know why people shy away from the old ways. Set it up and it will run, run, run.

 

[vision976]

You are correct av8or3! And I have purchased a points/condensor/stator plate and flywheel from an 041off of fleabay last night, so I know I'll get the saw to run with those. I have two old McCulloch mini-macs; a 120 and a 130. One has points the other the factory electronic ignition. Both run fine. We had points in most engines for decades, so it is a proven technology. I had a '67 Mercury Cougar a long time ago. It had points of course. There were CDI conversion kits that ran a very small current through the points to trigger the discharge of the capacitor. So the points would never burn and did not have to be replaced for a very long time. I ran one set for so long that the phenolic rubbing block broke off and left me stranded without ignition on I-5 at night. I put a replacement set of points in by flashlight.

 

[pioneerguy600]

I take it then the 309 coil setup isn`t a good swap for the 041. I have both Bosch and Sem sets squirreled away so I will make notes to not even bother trying them. So none of the 041`s I have here has lost spark, I could rob the module from my new one as it will never be started by me.

 

[wrenchit]

UPdate: 12/28/2021
Received SEM Ignition Module from eBay purchase from a Dolmar 309 Concrete saw. To fit it to Stihl 041 Super, it was necessary to have shorter M40 .70 screws. Stator plate holes aligned with 041 Super stator mounting plate holes. Necessary to mill a groove for the shut-off switch wire to pass through under the stator plate to the exit hole in the motor casing to reach the switch. Yellow switch lead is too short to reach the 041 shutoff switch and would require lengthening.

Dolmar SEM G/E ignition module high tension lead is too short to reach the 041 super spark plug. It is permanently fixed into the ignition module and cannot be unscrewed, unlike the stock SEM high tension lead. Would require a high tension lead splice, not a big deal.

It is not quite as tall as the stock SEM ignition module, about 1/10 of an inch shorter in height. It fits under the SEM flywheel without rubbing anywhere.

With it installed correctly (properly torqued down), I re-installed the flywheel and spun it up in the correct direction of rotation. I held the end of the high tension lead close to the cylinder head, watching for the spark. Did not see any. I dimmed the lights in the shop and spun the flywheel/crankshaft again, without a sparkplug installed. I saw the a very weak spark traveling between the wires of the high tension lead and the cylinder head. I installed a fresh battery pack in my drill, and spun the assembly up again. No spark this time. I varied the distance between between the wires in the high tension lead and the cylinder head, but no spark would appear. I tried several times. No spark.

What do I conclude?: I'm not sure the Dolmar SEM 309 coil will ever work to solve the no-spark situation I have in my Stihl 041 Super. At least not with the original SEM flywheel that came with the saw. The problem could be the SEM ignition unit being defective as it was "used". I don't know how to test it; the eBayer I bought it from, said it was "good", but there's a crack in the housing of the unit, that might have allowed something to enter the potting area, or even cracked a circuit board inside the unit.

I don't know.

Also, the location of the laminated iron plates which gather the flux lines from the magnets in the flywheel when it spins, are not located in precisely the same locations as the ones on the SEM original stator plate, so it is possible that not being the same relationship, the correct voltages necessary to fire a spark are available. I will post pictures tomorrow, showing the differences.

I don't think this suggested solution will bear fruit.

More tomorrow.

Points installed 041 and electronic ignition 041 saws had different magnet spacing in the flywheels so the Ignition modules/coils are not interchangeable if I remember correctly.

 

[av8or3]

If you go to points on your 041, you will need to score the entire setup. Stator plate with points and condenser and coil along with the rotor and flywheel from a non-electronic saw. The rotor is attached to the inside of the flywheel with screws and has the eccentric lobe needed for the points built in. Looks like I’ll have to put up a pic. to get my “points”across.

 

[vision976]

If you go to points on your 041, you will need to score the entire setup. Stator plate with points and condenser and coil along with the rotor and flywheel from a non-electronic saw. The rotor is attached to the inside of the flywheel with screws and has the eccentric lobe needed for the points built in. Looks like I’ll have to put up a pic. to get my “points”across.

Still waiting for the postman to deliver the stator plate and flywheel I bought off of eBay. The picture in the eBay listing of the stator plate, points and condensor, appears to be the same parts as in your picture. The flywheel picture in the listing does not appear like the one in your pictures, but was listed as a "points" style flywheel. We'll see when it arrives.

I"m assuming (perhaps incorrectly) that the fan from the SEM flywheel will bolt right up to the "points" style flywheel, (why would Stihl not make the fan a universal part that fits on SEM, Bosch and points type flywheels?)

What is the little light colored "felt washer" for and where does it get installed? And how important is it? I don't have one of those. Might have to buy or make one.

Thanks,

John

 

[av8or3]

Still waiting for the postman to deliver the stator plate and flywheel I bought off of eBay. The picture in the eBay listing of the stator plate, points and condensor, appears to be the same parts as in your picture. The flywheel picture in the listing does not appear like the one in your pictures, but was listed as a "points" style flywheel. We'll see when it arrives.

I"m assuming (perhaps incorrectly) that the fan from the SEM flywheel will bolt right up to the "points" style flywheel, (why would Stihl not make the fan a universal part that fits on SEM, Bosch and points type flywheels?)

What is the little light colored "felt washer" for and where does it get installed? And how important is it? I don't have one of those. Might have to buy or make one.

Thanks,

John

John, I don’t know whether that will bolt up to your fan or not. The white felt washer sits on top of the crankshaft oil seal. Probably protects or something. (Between the case and the stator plate.)
I am familiar with that style of rotor, just can’t remember where I’ve seen it.

 

[vision976]

John, I don’t know whether that will bolt up to your fan or not. The white felt washer sits on top of the crankshaft oil seal. Probably protects or something. (Between the case and the stator plate.)
I am familiar with that style of rotor, just can’t remember where I’ve seen it.

I was able to download a Stihl 041 parts list with exploded diagrams. The diagram shows the placement of the felt sealing washing, #1 0000 992 5740, under the stator plate and against the crankcase. Although the seal depicted in the diagram looks very different than the felt washer.

The parts list indicates only one fan 1110 086 0505 so the one I have should suffice. There are a couple of other seals and gaskets (besides the felt seal) which I might need: Items #26: 1110 086 8902 (Sealing Ring), #25: 1110 089 0500 (Gasket), #16: 1115 400 8200 (Dust Cap), #17: 1110 145 9001 (Plug). We'll see what arrives in the boxes from eBay.

The 041 electronic parts saw will arrive in a day or two, and that one might have a Bosch ignition system in it, (fingers crossed), so that's another possibility.

 

[Bret4207]

I'm still sitting on a 2100 Husky with no spark. I've put 2 different coils (SEM GA) in it with no luck. Flywheel seems to have plenty of magnetism. There has to be a way to fix this problem, it seems fairly common.

 

[vision976]

I'm still sitting on a 2100 Husky with no spark. I've put 2 different coils (SEM GA) in it with no luck. Flywheel seems to have plenty of magnetism. There has to be a way to fix this problem, it seems fairly common.

So I finally received the 041 Farm Boss "Electronic" parts saw; it was delayed in shipping due to the heavy snowfall event we had in the NW. I dis-assembled the fuel tank/recoil starter side case, removed the fan and looked at the flywheel part number. It matches the flywheel on my sparkless 041 super, so it has an SEM GA ignition system.

Removed the spark plug, grounded it to the engine case and spun the flywheel in counter-clockwise direction with a drill. Much to my surprise, a good, consistent spark was observed, so I will install the SEM stator plate in the 041 super to bring it back to life.

I may soak the dead SEM ignition system (the part potted in hard black epoxy) in MEK to see if I can dissolve the epoxy to be able to analyze the circuit and its parts underneath.

Bret4207: what method did you use to check the no-spark condition on your 2100 Husky? I had to shut off the lights at my workbench to be able to see the spark easily, as I spun the flywheel with a drill.

 

[vision976]

Just sayin, you can still prolly score a complete points/condenser magneto setup for around $100. I don’t know why people shy away from the old ways. Set it up and it will run, run, run.

av80r3: What is the correct lubricant to apply to the felt oiling piece that lubricates the cam on the flywheel?

Thanks, John

 

[av8or3]

av80r3: What is the correct lubricant to apply to the felt oiling piece that lubricates the cam on the flywheel?

Thanks, John

Just a drop of a light machine oil. (3 in1)You do not want to soak that pad. The oil will migrate and foul the points. Just a drop. Doesn’t look like enough but it is. Enjoy your saw.

 

[vision976]

I installed the SEM ignition system in the 041 super from the 041 Farm Boss Parts saw and the super works once again, so that's a happy ending.
I will now step through the 041 Farm Boss (it appears to have good compression, although I have not measured it. Peering in through the intake port at the piston as it goes up and down, doesn't show any damage, burning, metal transfer. So I will install the points ignition system into the Farm Boss and see if it runs well.

 

[vision976]

I installed the SEM ignition system in the 041 super from the 041 Farm Boss Parts saw and the super works once again, so that's a happy ending.
I will now step through the 041 Farm Boss (it appears to have good compression, although I have not measured it. Peering in through the intake port at the piston as it goes up and down, doesn't show any damage, burning, metal transfer. So I will install the points ignition system into the Farm Boss and see if it runs well.

Does anyone know if the SEM 041electronic flywheel will work the Bosch 041 electronic ignition system (stator plate, coil and Bosch Potted ignition system)? Or would I have to purchase a Bosch electronic flywheel.

I came across some Bosch 041 electronic ignition pieces on eBay and purchased one to have a spare for the 041 Super and the 041 Farm Boss, if ever needed. My thinking is that I can implement the "Foggy Sail" external capacitor fix with the Bosch electronic ignition module to remediate a no-spark condition, unlike the SEM electrionic ignition system, that has hard epoxy potting compound protecting the circuit and components within, which makes Foggy Sail's capacitor fix extremely difficult to investigate and implement. (Assuming the source of the no-spark condition is the same)

 

[KASH]

bump

 

[bell222jetranger]

I've have owned a Stihl 041 super AVE for 35 years and it finally died from a "no-spark" condition. This one has the SEM version of the electronic ignition. Researching the forums and looking on fleabay, I am unable to locate a replacement SEM coil. I believe the coil is an SEM Type GA coi which is used on Husky 2100's and some Dolmarsl, but I haven't pulled the flywheel yet. Any suggestions for replacement coils or other other solutions to make a spark at the right time? The saw ran really strong, excellent compression; the piston and cylinder show no scoring, so I'd prefer to fix it than junk it or sell it for parts. Thanks in advance for responses.

to whom it my concern / you can replace the SEM module with a Nova ll module and get it to run / it requires removing the SEM from the stator plate .

 

[vision976]

to whom it my concern / you can replace the SEM module with a Nova ll module and get it to run / it requires removing the SEM from the stator plate .

Good to know. I've read that there can be timing issues when using the Nova II module, sometimes they work correctly as installed, othertimes the Nova chip wires need to be reversed and sometimes the flywheel itself needs to have the woodruff key removed and the flyheel rotated some amount to bring the ignition back into proper timing.

 

[bell222jetranger]

I removed the SEM flywheel and replaced it with the Bosch one and adjusted pulse to match good spark.

 

[KASH]

What does adjust the pulse entail?
Kash