031 stihl question

[tomdcoker]

Just to let everyone know I enjoy reading the threads on this site and have learned a lot. Now for the problem the oil tank on my saw has a bad leak on the seam just below the muffler and It looks to me that to get to it I will have to split the case on the chain side of the saw. I need to know what problems I am going to incur other the obvious. Also one of the teeth is missing on the red impeller oil pump gear. I spun the gear by hand and it seamed to work but I wonder if it will work when the saw is running. Sorry about the long post. Any help would be greatly appreciated. Tom

 

[Marco]

You would have to remove the handlebar-airbox assembly so you could remove the cylinder, because the cyl. is attached to both halves of the crankcase and it needs to be removed so you can split the crankcase to replace your faulty gasket. A complete gasket&seal kit would be in order here, you may want to take a long hard look at your intake boot and pulse line also. I would think if you are going through the time and expense to fix a leak the saw should be worth a new/differant pump gear.

 

[cbfarmall]

If you want to save the saw, definitely split the case and replace the gasket. It's the hardest job there is when repairing a chainsaw as it involves totally tearing it down.

I got an 045 Super (first saw I ever worked on) that wrecked 2 cylinders and 3 pistons. At first I thought the oil leak at the gasket was just pesky, but it eventually dawned on me that the oil tank/crankcase gasket are one in the same. The saw sucked air and burned up the top end.

This is one respect that I give the edge to old Macs. Construction is simpler and more modular in approach.

Chris B.

 

[Justin Garrison]

I had an 031 that leaked bar oil and ran like crap, probably because of an airleak as cbfarmall said. I bought a new gasket, but never felt like putting the hours into that piece of a saw. It leaked gas as well, and the recoier actually caught like 1 out of ten times because one of the springs was gone. I just bought a parts saw for 5 bucks that was missing the clutch and all the oil pump gears. Swapped the over from my functioning piece and viola. I have a 32inch bar on it because that is what my piece saw came with. The only sprocket I have that will fit an 031 is a 404 one and that is the only 404 bar/chain I have. Strangely enough I use that saw for light work like rotten 10 inch dia crap. But what ever, the chain is square ground and I cant even sharpen that.

 

[tomdcoker]

Thanks for the quick turn-a-round on my question. I will defiantly replace the pump if I put that much labor in the saw. I agree with you on the construction of the stihl saws. I recently bought two 031 stihl's and like the way they work but do not like to work on them. I have a clinton, remington. homelite, wright, craftsman and david bradley and all are easier to work on than the stihl's. Thanks again, Tom

 

[Justin Garrison]

031s are truly terrible to work on. It is the most mispleasurable saw I have ever had the mispleasure to work on. If you have to take the top cove and air filter housing and gas tank off that is.

 

[stihltech]

031

Do not fear what you do not know.

With that said, an 031 is no harder to work on than anything else.
Remove the cylinder, air box and carburetor as one unit by removing the cylinder screws and pulse hose at the case. remove 6 case screws and 2 pins in the case. Heat the case evenly and apply extra heat around the
bearing,0n the case only. The case half will slide off. Use no more than a dead blow hammer on yhe end oft the crank, holding the case in the air so gravity helps and you are not driving the crank together, or bending it.

Clean it up, replace the gaskets, and reassemble. A couple of guide pins will help line things up. Put the screws in as fast as you can. One light tap on the crank will free it from binding. If it doesn't, reheat the case.

Any more questions, feel free to ask.

 

[Lakeside53]

Before you split the case, try to tighten up the existing screws. The gasket is just paper and may have been compressed or the screws got loose. I've done this few times an suceeded in stopping or massively reducing oil leaks from 031 and 028.

here's what would do :
1) get a set of 6 TORX head M5x18 from your stihl dealer.
2) loosen the cylinder screws slightly (these will liely be Allen key, not torx.
3) take out each of the pan head screws ONE at a time, and replace with the Torx screws. Snug then up nicely each time.
5) torque the Torx head screws to 8.8 ft lbs.
6) torque the cylinder head to 8.8lb

The reason to replace the pan head screws is that it really hard to get a decent amont of torque on them without messing up the heads, and they may already be messed up from the last guy! If I restore old Stihls, I replace ALL the screws with torx.

Do you have a service manual?