Stihl 031AV Ignition Conversion?

[Henry Finley]

A buddy gave me two old Stihl 031AV's. Very old, points and condenser type. Neither one will start, not that I expected it. I've been sitting here looking at youtube electronic conversion videos, and reading discussion sites, and none of it is definitive. One may show a simple conversion with an inexpensive chip. Others say that you have to switch to an "electronic" flywheel, or reset the timing on the original one (however THAT is done). I don't see one blessed procedure that is sure, foolproof, and doesn't cost an arm and a leg and a machine shop. As an aside, if I'm going to go through all that I figure a fresh coil in the process will cut out possible headaches. Some of the electronic conversion parts are $130 on the internet. The saw is not worth that. Not to me anyway. Somebody please straighten me out on the best and most expedient way to get the job done right. Thank you.

 

[Snowchaser]

Chip off ebay. Kawasaki/john deere #m70114. $14. 1 wire hook up. Mounting screw grounds it and the wire off the coil goes to the chip. 031 points saws require the flywheel rotated about 1/2” clockwise…… if I remember right. put a sharpie mark on the case and the flywheel. Then remove the key and rotate the flywheel clockwise 1/2” from your mark on the case. Tighten down the flywheel nut. If you don’t rotate the flywheel, the saw should still run, but will be sluggish and the muffler will glow orange cause the timing is so far off. I have never had a flywheel slip without a key. If you are concerned, you can put a drop of green loctite on the shaft. Green is for locking smooth shafts to each other, not threads. A little bit of heat and it’ll come off again.

 

[hotshot]

Think you meant CCW on the flywheel to advance the leading magnet/timing. Normal flywheel rotation is CCW. Do a search for “stihl 031 timing” by author Lakeside53 for more information.

I inserted an old thread pic below.

 

[Snowchaser]

Yep could be, been a while since i did one

 

[Henry Finley]

Thank you all for these answers. But not having pulled the flywheel off yet, I can only envision the flywheel and it's keyway being like most any other keyway I've ever seen. If you remove the key, then how can the flywheel stay put in time? And another question: One answer says 1/2 inch and another says 3/4. This is exactly what I spoke of in my first place. So much conflicting information out there. When it comes to ignition timing 1/4 inch is a lot.

 

[Snowchaser]

The flywheel and shaft is tapered so it holds it there.

 

[stihltech]

The two wire type of conversion module just needed the wires switched. Was a pretty common repair on a points saw 10 to 20 years ago.

 

[64poncho]

I left the point system in and used a Wima capacitor. I copied the way it shows in the photo. Had grind out a little of the case to fit. Used silicone & made a retaining clip.
Or it can be mounted remotely in the fan housing. There is more info on this site.
Search Wima.

 

[ZeroJunk]

I left the point system in and used a Wima capacitor. I copied the way it shows in the photo. Had grind out a little or the case to fit. Used silicone & made a retaining clip.
Or it can be mounted remotely in the fan housing. There is more info on this site.
Search Wima.




http://www.mouser.com/ProductDetail/wima/mkp4j032204j00kf00/?qs=sJjjjplDs9vUdEF04FfYfw==&countrycode=US¤cycode=USD

Your link didn't work, but I was curious what you could put in there. The right size electrolytic in a can being somewhere I can't find.

The problem I have had with old saws is when the coil opens, or shorts.

Bought a coil for an old Homelite out of Greece not long ago. NOS

 

[64poncho]

Funny, I tried the link before I put it in. And it worked.

Corrected link.

https://www.mouser.com/ProductDetail/WIMA/MKP4J032204J00KF00?qs=sJjjjplDs9vUdEF04FfYfw==

 

[MnSam]

I see it. Thank you for posting. That is my saw fix. I was wanting to add to this thread, but couldn't't find my picture (from 14 years ago). This saw still works great for me, although I don't use it often. It was my dad's and I wanted to keep it in usable condition. It produces a nice strong spark even with a slow pull. I believe I still have a Wima capacitor around if the OP wants to try this fix.

 

[64poncho]

I see it. Thank you for posting. That is my saw fix. I was wanting to add to this thread, but couldn't't find my picture (from 14 years ago). This saw still works great for me, although I don't use it often. It was my dad's and I wanted to keep it in usable condition. It produces a nice strong spark even with a slow pull. I believe I still have a Wima capacitor around if the OP wants to try this fix.

View attachment 1166250
View attachment 1166251

MnSam,

I copied your design. Wasn’t crazy about mounting it in the fan housing as others had demonstrated.
The saw is a coworker’s. Ask me to get it running. I got a lesson on this saw. Carb, fuel, impulse hose. Then crank seals. Everything I fixed, needed it. Thought I had it fixed but it was the capacitor that made it right!

 

[2StrokeFondler]

A buddy gave me two old Stihl 031AV's. Very old, points and condenser type. Neither one will start, not that I expected it. I've been sitting here looking at youtube electronic conversion videos, and reading discussion sites, and none of it is definitive. One may show a simple conversion with an inexpensive chip. Others say that you have to switch to an "electronic" flywheel, or reset the timing on the original one (however THAT is done). I don't see one blessed procedure that is sure, foolproof, and doesn't cost an arm and a leg and a machine shop. As an aside, if I'm going to go through all that I figure a fresh coil in the process will cut out possible headaches. Some of the electronic conversion parts are $130 on the internet. The saw is not worth that. Not to me anyway. Somebody please straighten me out on the best and most expedient way to get the job done right. Thank you.

First things first: I'd check if I have spark. If not I'd clean the points. Makes no sense to change anything if you have spark or can get one easily.

 

[Henry Finley]

After more study I discovered I already had all the capacitors I would ever want to fix these things. I do old-time radio repir, and have plenty of .22 non-polarized capacitors. So that problem is already licked. But about the points... since the cam is on the underside of the flywheel, it occurred to me how you adjust the point gap. I also noticed another thing. Either these points are jammed and no good, or they are SUPPOSED to stay open. They're not like Chevrolet engine points. It seems you can't hold them in your hand and push them open and the spring closes them. Are they supposed to stay open? When the cam comes around to hit the phenolic finger to open them, are they supposed to stay open till the cam goes around a little more and hits the back of the point arm to close them? If so, that would explain how you can set the gap, through simple trial and error. Or are these points just plain jammed? Because when you open them, they don't close. Not by it's own spring pressure anyway.

 

[Henry Finley]

Thank you all for the help on my thread. It was a bit of a learning curve, but I'm sure I have the situation under control. Do an internet search for points-and-condenser ignition on this model. All you get is bad ideas on going electronic. Turn the flywheel this way or that way. Throw away the key and use glue to keep timing. WHAT timing? When the Germans keyed a machine to keep time, you can bet your bottom dollar it was right. It's not for me to experiment with internet hairbrain ideas, no matter how well the videos say it works. I had the capacitors right here in my own ham radio room. Now all I have to do is wait on a set of good used points to come and I'm in business. But not without an convenyance of gratitude to you folks for morsels of wisdom left laying around. When you start a thread on the internet you take the consequences and glean the answers gratefully. Regards.

 

[ZeroJunk]

Thank you all for the help on my thread. It was a bit of a learning curve, but I'm sure I have the situation under control. Do an internet search for points-and-condenser ignition on this model. All you get is bad ideas on going electronic. Turn the flywheel this way or that way. Throw away the key and use glue to keep timing. WHAT timing? When the Germans keyed a machine to keep time, you can bet your bottom dollar it was right. It's not for me to experiment with internet hairbrain ideas, no matter how well the videos say it works. I had the capacitors right here in my own ham radio room. Now all I have to do is wait on a set of good used points to come and I'm in business. But not without an convenyance of gratitude to you folks for morsels of wisdom left laying around. When you start a thread on the internet you take the consequences and glean the answers gratefully. Regards.

Glad you got it going. de KM4AH

 

[stihltech]

And time the points too.

 

[Henry Finley]

And time the points too.

I finished up the saw and used it some today. I'm not sure what you mean to time the points. The cam lobe is on the underside of the flywheel. It is keyed in time. The points gap is set by removing 2 small plastic window covers and sitcking your feeler gauges down in the opening. I bought a set of used points on ebay for $7 because I didn't want to spend a lot of money on an unknown saw. The points were clearly worn, but not worn out. I set the points gap by dropping the flywheel into it's keyway, knowing I would have to take it back off for trial and error gap setting. The book said .012 to .016, so I split the difference at .014. after that I pulled the flywheel back off and put the window covers back in and tightened down the flywheel. Long story short, after getting it going I tuned the high, low, and idle stop on the carb and it runs like a champ. So my question is, what points timing? It's keyed.

 

[ZeroJunk]

See if there isn't a mark on the flywheel that should match up to a mark in the crankcase. Some degrees before top dead center. That would be where the points would open.

 

[wildwes]

Another way you can fix the condenser problem is to run some wires and remote mount a small chainsaw condenser somewhere else. I put them in the carburetor/air cleaner housing.

This is the one I used most recently. Disregard the description, it will NOT fit under the flywheel of a 031.

https://www.ebay.com/itm/172284295578