Stihl 031AV sprucin' up?!

[Newfman]

New member:

My wife's brother in law mentioned at dinner the other day that he had a Stihl Chainsaw that was running a little rough, and where should he take it to get it looked at. (He is 78). I had just finished rebuilding the carb on a 10 year old Husqvarna trimmer and for some reason I said, I can take a look at it for you. Like what the sam hill was I thinking?!?! I always just assume I can fix stuff. Don't know what that is all about. Anyhow, I should have known that this saw was vintage and likely bought at a yard sale from Christ himself, old man being a carpenter and all.

So, it is an older one from the looks of it. Ser. # 5228831. I want to give it a going through. Clean out the carb, and tune it up for him. Who is a reliable source for parts? Should I just take it in? What would you recommend for a good spring cleaning and sprucing up of this old work horse? I read that you can do short shots of carb choke cleaner to de-varnish the carb, but that just disturbs my sensibility a bit. Something about the lack of lubricity with choke cleaner as a fuel. Opinions?

Thanks for the info.

Dennis

 

[Saw Dr.]

That series of saw has ignition issues as often as carburetor issues. You will need to remove the carburetor in order to clean it properly. The intake boot should be checked as well as the impulse line. If it has points ignition (behind the flywheel) they'll probably need attention. You will need a puller to get the flywheel off. The fuel tank has to come off to get to the flywheel. There is a screw on the bar side that holds the fuel tank on, so don't miss that one when you're breaking it down. Should it have an electronic coil on it that is breaking down, you may have a problem. The points coils can be converted to electronic trigger units, but the electronic ones have to be replaced.

 

[Big L]

Subscribed ... Like to hear what you all have to say about this one. Mine was my father's, bought it new back in '80 I believe. Don't use it much, but have had it serviced at the local Stihl dealer in these parts ... don't be in a hurry though, took 'em some 3 or 4 weeks to get a few parts.

 

[Saw Dr.]

Subscribed ... Like to hear what you all have to say about this one. Mine was my father's, bought it new back in '80 I believe. Don't use it much, but have had it serviced at the local Stihl dealer in these parts ... don't be in a hurry though, took 'em some 3 or 4 weeks to get a few parts.

And some parts are discontinued now. Many dealers won't even work on them anymore.

 

[jrhjd318]

I am currently working on an 031Av myself that has been sitting for several years. I got it running somewhat with some fresh fuel mix, but did had to put a carb kit in yesterday. i got the kit on e bay for 10 bucks including shipping. Ran/sawed great for about 15 min then suddenly lost spark. After some trubleshooting i believe the plug wire is bad,going to dealer this morning to check on one and some other items. I can ebay one for 3 bucks but the shipping if almost as much as item price! When i restored my first saw, an 038 super, I had to compare prices/availabilty between dealer and ebay/online sellers to get all i needed.

 

[Newfman]

Thanks folks,
Just what I needed for onfo. I'll talk to Bob and see if he is still interested in getting this thing going. I do'nt mind doing the work. Certainly a good rainy day project. From the posts I have found so far, this was a good machine in it's day. May be worth the effort.

 

[MnSam]

Great saw, worth fixing in opinion.

 

[Ironhand]

The impulse line (behind the airbox) is also a problem area and should be replaced while you have it apart.

 

[Newfman]

Great, I will take care of that as well.

Thanks again,
Dennis

 

[mx239mx]

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

 

[Fish]

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

Go through the carb again and rebuild it correctly, replace the needle, and polish the seat. And hook up the impulse line.

 

[Newfman]

What is the recommended site for parts for these older machines? I would like to work up an estimate, and check parts availability. Are replacement points available, or is that going to require a changeover to electronic ignition. If a change over is required, am I looking at a different flywheel as well?

 

[Newfman]

Wel it has a Waldbro carb. I got that out. I am having an issue with the plate it is mounted to. I cannot see where the impulse line runs to to disconnect it. The boot is disconnected. There is so much crap in there, I am reluctant to spray a cleaner in there, for fear of getting it into the intake. I was planning to disasemble it, cover the intake and clean it then. If impulse lines are no longer available and this one is un-damaged, I'd like to keep it that way. Any suggestions?

Before disassembly, I ran the saw up, It started pretty well. It is a little balky getting to speed, but reaches the top and runs fairly well. It four strokes at the top end. It is possible it has never been part before. It was incredibly loud! Ear splitting! I found all three screws that hold the muffler on to be at least four full turns backed out. I will find some high temp lock-tite for reassembly.

So far so good. i just need to source my carb kit. My Brother in Law doesn't want to get into the ignition part of it. So, it will be a Carb job and a clean up and we'll see how she runs from there.

The plate that the carb mounts to has a serial number; 9 1113 141 0400 Is that significant to the carb, or just that plates part number?

The chain tension adjuster seems a little touchy. Like you just about get it right and it releases. Is that an easy part to get? He gave me the saw with the chain just dangling down. I could fit the tip of my index finger between the chain and bar. I know he has been running it that way. Scary.

Thanks for the help.

Cheers,
Dennis

 

[Ifishsum]

The carb air box you're referring to will come off fairly easily - you just have to remove the top handle and cover, plus a couple of screws and carefully push the intake boot through the carb box (leave it connected to the cylinder for now). That will let you clean up the intake side of the cylinder and also inspect your intake boot and impulse line. I'd replace the impulse line regardless, and if the intake boot shows any cracking at all replace that as well. Both of those parts are pretty easy to find on ebay.

You need the part number from the carb itself to get the right kit - the number from the air box is not related to the carburetor.

 

[angelo c]

loggin in

 

[angelo c]

That series of saw has ignition issues as often as carburetor issues. You will need to remove the carburetor in order to clean it properly. The intake boot should be checked as well as the impulse line. If it has points ignition (behind the flywheel) they'll probably need attention. You will need a puller to get the flywheel off. The fuel tank has to come off to get to the flywheel. There is a screw on the bar side that holds the fuel tank on, so don't miss that one when you're breaking it down. Should it have an electronic coil on it that is breaking down, you may have a problem. The points coils can be converted to electronic trigger units, but the electronic ones have to be replaced.

Doc,
Where is the last screw holding the tank on. I've been trying to find it for a while. these older saws are not so much fun to break down with all the miss matched screws and t-27 bolt lengths and sizes. I have good spark on this one but can't get it to fire. fuel and compression but no bang.

A

 

[Fish]

Doc,
Where is the last screw holding the tank on. I've been trying to find it for a while. these older saws are not so much fun to break down with all the miss matched screws and t-27 bolt lengths and sizes. I have good spark on this one but can't get it to fire. fuel and compression but no bang.

A

There is a hidden one on the right side, if the clutch was a clock, it would be @ the 7 oclock hand area, a couple inches from the clutch.

 

[Fish]

That series saw originally had no torx fasteners, just cheese heads and allen heads......

 

[angelo c]

There is a hidden one on the right side, if the clutch was a clock, it would be @ the 7 oclock hand area, a couple inches from the clutch.

thanks Fish,
I found the one but still can't get the tank off. must be something else holding it up.

copy on the screws and what nots holding this thing together. That's why I like the newer style Stihls because a t27 and you can pretty much break anyone down and put it back together w/o ever looking for another lost tool

A

 

[MnSam]

Wow. There is so much going on in this thread I'm not sure what or who to advise to! I will say when the 031 is dialed in it is an awesome running saw. Take the time to read up, and take the time to break the saw down and inspect the parts. You need good spark, and fuel to the spark, and an engine that draws the fuel into it (IE: suction). These saws are getting to be 40 years old, maybe it is time to look at the the seals.

Also, I am in favor of keeping the points over converting to the atom/nova/omega modules. My 2¢.