Stihl 031 problem

[pastryguyhawaii]

I was given this 031 to get running if I could. It has new rings, clutch side crank seal, Proline carb & fuel line/filter, & new impulse line. Pass pressure vac test. I tried both the Kawasaki & Oregon ignition chips with the Oregon in now. Both work with timing advance. The problem is it starts in a couple pulls, runs quite well for about 3/4's of a tank. It will then just stop and will not restart. Spark looks the same as the beginning & the plug does not get wet. Wait a day and starts right up. I have done this quite a few times with the same results. Oh, and the intake boot looks good.
Any suggestions would be appreciated.

 

[burnses]

classic bad coil looses spark when it heats up.....coils still have spark externally when checking but not enough under cylinder compression.....tank might not be venting...that tends to be a gradual stop to the engine....

good luck

 

[pastryguyhawaii]

classic bad coil looses spark when it heats up.....coils still have spark externally when checking but not enough under cylinder compression.....tank might not be venting...that tends to be a gradual stop to the engine....

good luck

Thanks for the reply. I was afraid that it might be the coil, though I am real weak on electrical issues. It just stops abruptly. Unfortunately, coils are out there but are not cheap.

 

[HarleyT]

The Oregon and Kawasaki chips are the same, but the Oregon can be hooked up in reverse. They work on the 032.

The 031 takes Stihl #1118 400 1001. Not sure what aftermarket chip works on that model.

 

[HarleyT]

I save the triggers off of old 009,010, 011 saws, as they have the chip for the 031.

 

[a. palmer jr.]

Easy to check the tank vent, just take the fuel cap off and see if it runs..

 

[pastryguyhawaii]

Easy to check the tank vent, just take the fuel cap off and see if it runs..

I did try that, still a no go.
The coil heating up makes sense to me. It always cuts out after the same amount of running.
It's a decent running saw, I like it. I will pass it on to the original owners when I get it right.

 

[a. palmer jr.]

It could easily be a coil separating when hot then going back together when it cools off. Those coils are fairly heavy duty, that's the reason it's already lasted so long.

 

[Echo26]

I was given this 031 to get running if I could. It has new rings, clutch side crank seal, Proline carb & fuel line/filter, & new impulse line. Pass pressure vac test. I tried both the Kawasaki & Oregon ignition chips with the Oregon in now. Both work with timing advance. The problem is it starts in a couple pulls, runs quite well for about 3/4's of a tank. It will then just stop and will not restart. Spark looks the same as the beginning & the plug does not get wet. Wait a day and starts right up. I have done this quite a few times with the same results. Oh, and the intake boot looks good.
Any suggestions would be appreciated.

Mine floods like hell , it was a good coil(stihl 009), checked resistance as indicated in manual and got same values. Now the spark just became weaker and magically disappear. Turned out the high tension wire ****ed up and touching ground on some sort. Stopping the spark to generate.

 

[MudgeHollowBeaver]

The Oregon and Kawasaki chips are the same, but the Oregon can be hooked up in reverse. They work on the 032.

The 031 takes Stihl #1118 400 1001. Not sure what aftermarket chip works on that model.

I replaced the points/condenser setup in both my 031av saws with am aftermarket 98220 universal ignition chip connected for negative ground. Have cut a lot of wood with them since this upgrade. Some posts indicate that chip should be connected in positive ground configuration but I found that my saws would not start connected that way