Stihl 031AV sprucin' up?!

[McCulloch1-52]

I have a 031 trying every thing to get it running but when it does runs acts up new carb kit still has problems just to let you know I would not waste my time on it to much You will get a big headache.

:beat_brick:

 

[MnSam]

I'll take it off your hands for ya if your not too far away :msp_smile:

 

[redoakneck]

Great saw to re-build. You must do a compression test and a pressure/ vacuum test to make sure the piston and seals are ok. Carbs are adjustable and you can still get parts for them. Some of the parts, like the clutch shoes and one of the seals, are the same as an 028.

I have fixed 8 of these and they all idle and run very well. The av and the gas milage are vintage 70's if that matters to you. Most common things I found wrong are the capacitor goes bad so no spark (WIMI fix for a dollar), the seals, and the carbs need cleaning or re-built.

 

[angelo c]

so lots of you guys are familiar with this breed.

Mine is a friends who gave it to a dealer and he said no ignition parts could be had. I offered to take a look. It has good spark so all along I've been convinced it was fuel related as compression is +135psi. I bought a second "parts" saw from 08f150 (scott) just because it was cheaper to donate parts then R and R them till I isolated issue. It has a coil as best as I can tell and see nothing that looks like points at this stage. My question is can there be a "weak" spark and is there a way to test "amount" of spark. I have the inline "lisle" light tester and looks ok by eye. I have replace the known running carb with unknown and not had success. And placed unknown carb on known saw and not run either so no help there.
Funny, I cna break down and diagnose a 036 in about an hour or so but this breed has me cursing...unfamiliarity will do that...

 

[Fish]

Yes, "good" spark is hard to determine. I like those crude testers with the extra wide gap, because if they can "snap" those on every revolution, your spark is very good.
Going by color, it is too subjective.......

 

[Fish]

I have been working on this junk for years, and have not been able to fix one yet..........

I just throw out ideas and see if one sticks............................................

 

[angelo c]

Yes, "good" spark is hard to determine. I like those crude testers with the extra wide gap, because if they can "snap" those on every revolution, your spark is very good.
Going by color, it is too subjective.......

thanks Fish, but I was hoping for a different answer... hehe

 

[MnSam]

Detailed pictures speak volumes.

 

[a. palmer jr.]

I have been having issues with a 031AV and it was driving me so crazy to the point that I have not touched it in about 3 years. It was given to me 3 years ago from a friend and he had the saw sent out to be looked over because it wouldnt run right. They put a new carb kit in it, never hooked up the impulse line and it would start but just run like crap. I took the carb apart and adjusted the metering valve, the saw was converted to elctronic ign and I opened up the low screw 1 full turn as well as the high screw on the carb and it just pours gas right back at you. Close the high screw but not touch the low screw it wont pour gas right out of the carb. Turn the high screw 1/4 turn it will just start pouring gas. Im just tired of looking at it just sitting there and its in very good shape for its age, it would be nice to see her run...any ideas???

Bryan

It sounds to me like the inlet lever in the carburetor is set too high. Depending on what carb is on it you can go to their website and get instructions on rebuilding and setting the carb. If it's a Walbro you can use the "W" tool for setting the height.

 

[Newfman]

Running but Binding

So, I just posted this here. . .somewhere, but it seems to have gotten lost.

I got the saw back together, but am still having issues with the chain tension. He had it set so loose, you could see the whole of at least three links, just hanging down from the bar. It turns out, that if you try to set the tension beyond that, the chain binds up. I thought the chain cover may be binding so I removed it and bolted down the bar using fender washers for spacers. Same thing, as soon as you get the chain slightly tight, it binds.

I am fixing this saw up for him on my own nickel (up to this point) so I don't want to just start throwing parts at it. I cannot seem to find a place in the bar that the chain binds, and the clutch seems to turn freely by hand without the chain and bar. How do you test the clutch? I'm leaning towards a new bar and chain, but could use some expert advise. I might also add, the tip of the bar looks a little burnt, so this may have been an issue for awhile. He may have even run it out of bar oil, as the reservoir was empty. :frown:

It is a 16 inch bar (16" of cutting length, 18 overall), so, if I replace it, what is a good source for a bar and chain for this saw? I cannot read the markings on the bar, so if you have the specs. for the parts, i would greatly appreciate it.

Cheers,
Dennis

 

[McCulloch1-52]

Take a picture if you can.

 

[Ifishsum]

Is it a sprocket nose bar? You may be able to replace the nose on the bar if that's your problem. Take a close look at the drive sprocket as well. The bar should be a 3003 mount.

 

[McCulloch1-52]

Could be a bent bar.

 

[a. palmer jr.]

I've got an 031AV that I've been doing a little sprucing up on. I have all the parts...somewhere.

 

[Fish]

There is nothing worse than smoked ham piston damage..........

 

[a. palmer jr.]

There is nothing worse than smoked ham piston damage..........

No piston problem on this one. The last owner said it had a bad coil but I finally got it to produce spark. Now it appears the carb needs rebuilt. The smoked ham box is the best thing I could find to put small parts in so I won't lose them on the floor.

I cleaned the points and set them at .015, just guessing at what they should be. At least the spark is there now.

 

[MnSam]

They should be .012 - .016. Those parts should make a nice looking saw.

 

[Fish]

.016 is the closest....

 

[a. palmer jr.]

They should be .012 - .016. Those parts should make a nice looking saw.

It may be nice looking but it still doesn't run very well. I put it back together same day after checking coil and points, wires etc. with a continuity meter. It has spark and I cleaned the carb and put new gaskets in it while I had it apart and the thing will hit but won't continue to run, just hits a couple or three times and dies. I don't have a great way to check the condenser but since I'm so good at tearing these 031s down (tore down, put together 4 this weekend) I may try one of those Mega Chips in the ignition to see if I can get her going. Another one I had worked great until I washed it off now it doesn't run..should have left it dirty.

 

[a. palmer jr.]

.016 is the closest....

I wonder if anyone has ever tried a Nova II module on an 031? I just ordered one to try. The ad said "will not work on most Stihl trimmers or chainsaws." I can't imagine why it would work on my Echo 750VL and not work on a Stihl 031. They look to be the same basic setup.