Stihl 031AV Spark

[Bryxe]

I have a 031AV that I got for free in the garbage, pulled the cord has great compression, carb has been cleaned, it did spark the first pull but very inconsistently. I’ve done some research but am still confused, from what I’ve found it’s most likely a condenser, before I order a replacement I want to test the coil. I have the ignition coil off, wondering how to test it. I have a multimeter set to 20k ohms and there is no continuity between the spark plug wire and the ignition coil bracket. I’m not really for sure how to test the ignition coil itself but I think I did it right.

Does anyone have a for sure test I can run on this thing, I’m wanting to switch it from points and condenser to chip, probably won’t if the coil is bad because they’re so expensive used.

 

[Ando81]

Is it possible that the kill switch wire is loose or not right? I had a loose kill switch wire once and the saw would play up randomly which was annoying but a simple fix. Best of luck.

 

[L34]

At a guess,
Spark plug wire to bracket 8-10kohms
Kill switch wire terminal to bracket 0.1-0.2 ohms

 

[rd35]

Based on your description, you should be seeing continuity from the wire to the core frame. I would try disassembling the plug wire cap to make sure the contact ring (coil spring with piercing point) is making proper contact with the conductor in the plug wire. Sometimes those little springs will get burned away at the point and you have to bend a new "L" on them and sharpen it to poke through the wire insulation. Otherwise, sounds like you have a bad coil. I was always told these coils rarely die...and that may be true! But I did come across a bad one a few months ago on an old 041AV so I know it can happen.

 

[a. palmer jr.]

It is very likely that the condenser is the culprit. You can check the coil with an ohm meter but the coil must be disconnected from everything. Should read low ohms on the primary and high ohms on the secondary which is the spark plug wire at the end... I've used the WIMA capacitors to replace the condensers in those saws fairly successfully...

 

[oldercut]

It is very likely that the condenser is the culprit. You can check the coil with an ohm meter but the coil must be disconnected from everything. Should read low ohms on the primary and high ohms on the secondary which is the spark plug wire at the end... I've used the WIMA capacitors to replace the condensers in those saws fairly successfully...

Hi, I saw your comment regarding this spark problem on an 031av and I have a similar problem. Can you
suggest a source for the replacement capacitor you mention ? I get spark, but intermittently. Thanks

 

[HarleyT]

Sounds like someone had put on an electronic module, put up some pics.

 

[HarleyT]

The points and condenser are under the flywheel, the electronic ignition chip was mounted on one of the coil legs with a special bracket.

 

[a. palmer jr.]

Hi, I saw your comment regarding this spark problem on an 031av and I have a similar problem. Can you
suggest a source for the replacement capacitor you mention ? I get spark, but intermittently. Thanks

Yes, I bought mine from ebay, not very expensive. If you want I can probably find the specs on the capacitor, it's somewhere on this site if I remember correctly. This WIMA capacitor replaces the condenser so will work only on points saws.
Okay, I found it. It's is .22 micro farad and 630 volts. It has printed on the left side Mks 4 and under it is printed D6. It measures a tad over 1/2 inch wide and height is a little less. Hardest thing is to find a place to mount it so the flywheel doesn't grind it up...

 

[oldercut]

Yes, I bought mine from ebay, not very expensive. If you want I can probably find the specs on the capacitor, it's somewhere on this site if I remember correctly. This WIMA capacitor replaces the condenser so will work only on points saws.
Okay, I found it. It's is .22 micro farad and 630 volts. It has printed on the left side Mks 4 and under it is printed D6. It measures a tad over 1/2 inch wide and height is a little less. Hardest thing is to find a place to mount it so the flywheel doesn't grind it up...

I apologize a.palmer as I had already found the cap. value at .2 microfarad in the service manual. Someone
else had posted a link to it on another thread on this site. Were you able to install this in a space under the
flywheel or did you place it outside. I don't know the size of the WIMA cap. but did find their website.
Perhaps e bay will still have some. My initial test of my cap. indicated it was ok, but
that was just an ohm meter test showing it was not shorted. My coil also tests ok ( low resistance on primary
and 7 k ohm on secondary. Thanks for you information. I know this saw is old but I hate to give it up. I have
had it since new. Maybe. I need to give in and look for a new saw.

 

[KASH]

A good saw make sure the points are clean after you run a points file or emery cloth on the points blow the area clean with air and I spray brake cleaner on the point contacts then pull a CLEAN business card threw the closed points.Set point gap at 14 to 16 thousands.
Kash
The wima caps work great you can even mount it in the old condensor if you are a member of the correct police.

 

[a. palmer jr.]

It's possible you need a new set of points instead of the capacitor. I think I ended up putting the cap inside the flywheel opening, these things aren't very big, about .75 longX.50 high and about.25 thick. You just have to solder a couple of wires on them. I checked it out and ebay does have them.

 

[oldercut]

It's possible you need a new set of points instead of the capacitor. I think I ended up putting the cap inside the flywheel opening, these things aren't very big, about .75 longX.50 high and about.25 thick. You just have to solder a couple of wires on them. I checked it out and ebay does have them.

I have filed/dressed and cleaned points, look nice and flat, gapped to .015. Your capacitor solution sounds
promising. Thanks so much for the details.

 

[a. palmer jr.]

I hope it helps. Pretty sure if you get the WIMA capacitor you'll need the .22uf but not sure how high you'd have to go on the voltage. Mine is 630 volts but you could possibly get by with a smaller voltage if you had to.

 

[KASH]

The 630 volt is fine I have used them on rea;lly old outboard motors.They will last a lot longer than the old caps but I have a 1926 Johnson and a 1924 Evinrude still running with original condensors

 

[oldercut]

I have a 031AV that I got for free in the garbage, pulled the cord has great compression, carb has been cleaned, it did spark the first pull but very inconsistently. I’ve done some research but am still confused, from what I’ve found it’s most likely a condenser, before I order a replacement I want to test the coil. I have the ignition coil off, wondering how to test it. I have a multimeter set to 20k ohms and there is no continuity between the spark plug wire and the ignition coil bracket. I’m not really for sure how to test the ignition coil itself but I think I did it right.

Does anyone have a for sure test I can run on this thing, I’m wanting to switch it from points and condenser to chip, probably won’t if the coil is bad because they’re so expensive used.

Have you solved this issue with your 031 ? It has been awhile since you asked about it. I have some information
but will wait until I hear what happened.

 

[a. palmer jr.]

With the coil disconnected, assuming it is a points coil, ground the black wire on the meter to the bracket and put the red wire on the spark plug wire end. Make sure the plug wire end is okay and it should be okay to use the 20k ohms setting, should show something on the meter. The primary side should read a much lower ohms reading, you could use the X1K reading and get close to zero on the meter. Of course the best way is to substitute it for a known good coil.

 

[a. palmer jr.]

The 630 volt is fine I have used them on rea;lly old outboard motors.They will last a lot longer than the old caps but I have a 1926 Johnson and a 1924 Evinrude still running with original condensors

I just mentioned that because I noticed the 630 volt capacitors are a bit more scarce on ebay than some of the lower voltage ones.