031 AV Conversion

[Keith1951]

I have a Stihl 031AV with Electronic Ignition that I bought new. It now starts ok but immediatley cuts out as soon as I tilt the saw to the wood. It looses spark and if I let it sit it'll start in 10 minutes or so and do the same thing again. I took it to the local Stihl shop who replaced the fuel filter. Still did it. I took it back and they confirmed no spark after running it in there wood lot. Now everything that I hear and read tells me the electronics, e.g. ignition armature, is shot. I've called all over gods creation and cant find any replacements, new or used and ebay is a pain in the neck. Stihl gave me the name of an outfit in SD that supposedly has adapted a new armature to fit both 031 and 028 for $125 delivered. They say they have been doing this for 4 years successfully. This SD outfit tells me I need to modify the saw a bit but it's "not to difficult". The Stihl corporate guys, @ an 800 number, say the word is that this modified armature has been pretty successful. So, I have a few questions. 1. Does it sound like the armature is bad or could it be something else? 2. If so, what else? 3. Are there any other options? 4. Can anyone confirm the success of the SD armature? 5. If, it is "not to difficult" (I restore british sports cars from the ground up so the mechanics dont scare me) will the saw be compromised? I'd rather rebuild the old and previously dependable all metal 031 than buy a new "composite plastic" one for $400. Your help is appreciated. Keith1951

 

[stonykill]

if you post this in the chainsaw forum, someone there should be able to help you. I also have an 031, fantastic small saw.

 

[Cam501]

I have a Stihl 031AV with Electronic Ignition that I bought new. It now starts ok but immediatley cuts out as soon as I tilt the saw to the wood. It looses spark and if I let it sit it'll start in 10 minutes or so and do the same thing again. I took it to the local Stihl shop who replaced the fuel filter. Still did it. I took it back and they confirmed no spark after running it in there wood lot. Now everything that I hear and read tells me the electronics, e.g. ignition armature, is shot. I've called all over gods creation and cant find any replacements, new or used and ebay is a pain in the neck. Stihl gave me the name of an outfit in SD that supposedly has adapted a new armature to fit both 031 and 028 for $125 delivered. They say they have been doing this for 4 years successfully. This SD outfit tells me I need to modify the saw a bit but it's "not to difficult". The Stihl corporate guys, @ an 800 number, say the word is that this modified armature has been pretty successful. So, I have a few questions. 1. Does it sound like the armature is bad or could it be something else? 2. If so, what else? 3. Are there any other options? 4. Can anyone confirm the success of the SD armature? 5. If, it is "not to difficult" (I restore british sports cars from the ground up so the mechanics dont scare me) will the saw be compromised? I'd rather rebuild the old and previously dependable all metal 031 than buy a new "composite plastic" one for $400. Your help is appreciated. Keith1951

I don't know too much personally about that armature, but that's the same place we send people to for parts that stihl no longer makes.

 

[Railomatic]

Normally when the spark goes walk abouts it points to a HT or high tension coil problem, when the system has cooled down sufficiently the coil tends to reconnect inside and the spark returns and the same process starts over again.

You can do a continuity test on the field coli and the main coil which show good reading, but as soon as you fire things up the magneic flux will break down the spark under load, so don't take dry readings as gospel.

First check for any loose wires on the cut off switch or for the HT lead rubbing onto the casing, or the low tension coil for looseness then go through the process of starting and running the saw.

To check if this is the case, leave the spark plug cover off of the saw, as soon as the engins cuts out again, leave the saw on its side, pull off the plug cap, leave the plug in the engine and quickly bung another plug into the cap straight away and pull her over and check for a spark, if its not there, you have your answer.

You know the engine runs for a while so its unlikely to be a fuel problem, if there is any back firing of the engine this could be ignition, another thing that happens with an older engine is the crank seals get worn which gives the same kind of senario, just because the engine cuts out whilst on her side doesn't mean its a fuel problem.

Also check to see if the plug is wet, if it is dry then this point to a fuel problem, with worn crank seal the crankcase pressure is also effected and the fuel does not reach the top of the cylinder properly, also leaving a dry plug.

There are only three main things that can go wrong with a two stroke, fuel, spark or compression, if the saw keeps running when its in the upright position then it is unlikely to be an ignition problem, how long does the saw run for as long as it it stood upright ??.

If all these things check out, also inspect the carb diaphram and check for main bearing play.

I searved my time as a motorcycle engineer, where we also repaired chainsaws, generators and outboards, if these things do not show anything, give me a PM and I will try to help you further.

Raily.

 

[stihltech]

module

There is a module under the flywheel that is usually the culprit on this saw.
Atom makes a replacement module, it would be the cheapest way to go. Yes, it could be a coil, but the ratio of modules to coils is about 10 to 1.