050 051 075 076 Info Thread

[Rockfarmer]

The importance of a vacuum test can't be overstated even if a pressure test doesn't show any major issues..., especially at the crank seals. A bad oil seal will often seal with pressure and still leak under vacuum like a one way check valve. And finding that type of vacuum leak can be tricky since using pressure easily masks it. If using pressure to look for bubbles at a seal, just use very low pressure and soapy water. Apply just enough pressure to keep the soapy solution from entering the bearings/case, but not enough to close the leak. The other way is to use vacuum with oil or light grease at the seals to observe if the oil/grease is drawn in around the seal and/or the leak stops as observed on a pressure/vac gauge.

Agreed, the principal of the saw running is that it creates vacuum not pressure,.. If it does hold pressure but not vacuum then do as Pogo advises. I think I like oil better than soapy water though. Usually I watch the vacuum gauge dropping. If oil hits the spot where it’s leaking it will stop or slow then you know you found it. Also turn the crank while testing, sometimes cranks are bent, races worn, all kinds of weird crap. Synthetic oils are not the best for old saws. Too slippery. I’ve seen bearings actually spin in the case when they get worn. The balls are so slippery from the synthetic oil they skid and fail. But that’s a different subject and the gazillion dollar debate, lol! Cheers Pogo! Happy new year!

 

[PogoInTheWoods]

Back at ya Rocky! Good to see ya!

 

[ZachAK]

A carb question for anyone who may have ran into a similar issue.

I have two 076 AV Supers with Walbro carbs, but both carbs aren't the standard WJ-112 or WS26A. The carbs have no numbers stamped on them. We looked everywhere. My Stihl mechanic ordered the rebuild kit for the closest saw, and it was clear that it wasn't right, as there's no screw to the right side of the "Walbro" as the Stihl diagram shows for the others.



I'm almost 100% certain these are original carbs, as both saws are low hours and hadn't run since the 80s. The existing carbs are in decent shape, but I'd sure like to have a kit for anything that goes wrong.

Thanks in advance!

Zach

 

[Rockfarmer]

Sometimes the carb kits come with several different style diaphragms. You might be in luck and get the right one with your set.

imho a “super” isn’t a super without a walbro carb. They are bigger and better than the tillies.

 

[ZachAK]

Sometimes the carb kits come with several different style diaphragms. You might be in luck and get the right one with your set.

imho a “super” isn’t a super without a walbro carb. They are bigger and better than the tillies.

Thanks Rockfarmer! Yeah, the rebuild kit wasn't quite right. I'm trying to get in touch with Walbro, but I'm guessing they'll be clueless without a number.

Sure a gutsy saw.

 

[Rockfarmer]

I’ve had terrible luck with the dealers in my area. I know other parts of the country are much better. The rebuild kits I’ve ordered off eBay have worked and as I said had different diaphragms with a set that worked. Wish I could help more, cheers B

 

[DND 9000]

Remove the old gasket on the side, it`s possible that the model description is there.

 

[Rockfarmer]

DND is correct. Remove the gasket. Here is a new WS-11.

 

[ZachAK]

Remove the old gasket on the side, it`s possible that the model description is there.

Hot damn! You're probably right. Thank you!

We didn't take it off because Stihl doesn't supply the gasket anymore—but surely we can find one. I'll report back. Might be a bit because my saws are with the mechanic.

 

[Rockfarmer]

Sometimes if you soak the gasket with just about anything you can carefully peel it off with a putty knife on the edges where it starts to loosen and reuse.

 

[DND 9000]

Which carburetor do you have?

 

[ZachAK]

Thanks again everyone. I've ordered new gaskets and some other Stihl parts from Australia—parts they have readily available but Stihl doesn't stock in the US. So once I have new gaskets in hand and can see that they fit, I'll peel the old ones off and check for a carb number. I should have those in a month or so, and will post what carb I have on my saws.

A chainsaw buddy in Australia ordered my parts via his local dealer. Sounds like pretty much everything for the 076s is still available down there, and I was surprised at how inexpensive the parts are with the OZ/US exchange rate.

BTW, the new 076 parts list/diagrams available to Stihl mechanics in the US doesn't show all of the parts for the 076AV Supers. Some numbers were missing, and the torsion spring for the brake didn't show in the diagram. I downloaded a 2004 version of the parts list here:
https://www.smaf-touseau.com/doc/45

 

[ZachAK]

Which carburetor do you have?

I'm still trying to figure that one out...once I have replacement gaskets, I'll peel them off and see if there is a number.

 

[Rockfarmer]

Has anyone tried these new aftermarket clutch's? They have no fiber on the shoes. Im running out of clutch shoes that are not cracked and chipped on the fiber lining. The 056 clutch's had no fiber on the stock shoes and they work just fine. Now thats more of a felling, bucking saw than the more desired use of the 076 which I build for (mostly) milling. Any thoughts on the clutch performance as far as rpm engagement, heat, wear on the drum and overall performance of using the shoes with no lining? Im going to try it within the next month or so. Ive got about 15 cord of logs, some millable and one cedar log I need to mill for a table. Just throwing it out there, Cheers!

 

[ncrile]

Hey all!
This may be a replace crankshaft question..... I'm trying to rebuild an 075.
I've replaced the seals, bearings AND crankshaft (my bad on the crankshaft). When I tighten down the flywheel, it won't spin (it bottoms out on the crankcase). Leaving it a tad loose, it's fine. I thought i had the bearings seated in all the way. The case went together fine. It appears the crankshaft has no room to move in (towards the flywheel). I've tried the tap with a rubber mallet trick The crankshaft is a new aftermarket Tecomec shaft. I'm scratching a hole in my head.

Any input appreciated.

 

[ncrile]

Has anyone tried these new aftermarket clutch's? They have no fiber on the shoes. Im running out of clutch shoes that are not cracked and chipped on the fiber lining. The 056 clutch's had no fiber on the stock shoes and they work just fine. Now thats more of a felling, bucking saw than the more desired use of the 076 which I build for (mostly) milling. Any thoughts on the clutch performance as far as rpm engagement, heat, wear on the drum and overall performance of using the shoes with no lining? Im going to try it within the next month or so. Ive got about 15 cord of logs, some millable and one cedar log I need to mill for a table. Just throwing it out there, Cheers!

I bought one from HL Suppy but have yet to get my 075 going. Will let you know If I do.

 

[Rockfarmer]

Hey all!
This may be a replace crankshaft question..... I'm trying to rebuild an 075.
I've replaced the seals, bearings AND crankshaft (my bad on the crankshaft). When I tighten down the flywheel, it won't spin (it bottoms out on the crankcase). Leaving it a tad loose, it's fine. I thought i had the bearings seated in all the way. The case went together fine. It appears the crankshaft has no room to move in (towards the flywheel). I've tried the tap with a rubber mallet trick The crankshaft is a new aftermarket Tecomec shaft. I'm scratching a hole in my head.

Any input appreciated.

where the flywheel is furthest on the crank the crank measures 13.5 mm and is about 5 cm from case. That’s the inner mark on the crank. From the case to the threads is about 2.5 cm. I always press the bearings into the cases until they bottom out. Then I press the crank into one side, put the gasket on and pull the case together with long screws. Always the crank is tight and does not spin freely because it’s under pressure. To release the pressure I put the spider on the clutch side flush and tap it with a hammer. I do the same on the flywheel side. This relieves the pressure, centers the crank and it spins sweetly. I’ve never used aftermarket crank. I have a box of oem if you want one. Are you using the same flywheel that came with the case. Shouldn’t matter but might. 075,... is it a roller case (points) or electronic?

 

[Rockfarmer]

where the flywheel is furthest on the crank the crank measures 13.5 mm and is about 5 cm from case. That’s the inner mark on the crank. From the case to the threads is about 2.5 cm. I always press the bearings into the cases until they bottom out. Then I press the crank into one side, put the gasket on and pull the case together with long screws. Always the crank is tight and does not spin freely because it’s under pressure. To release the pressure I put the spider on the clutch side flush and tap it with a hammer. I do the same on the flywheel side. This relieves the pressure, centers the crank and it spins sweetly. I’ve never used aftermarket crank. I have a box of oem if you want one. Are you using the same flywheel that came with the case. Shouldn’t matter but might. 075,... is it a roller case (points) or electronic?

obviously the roller case has a different crank,..

 

[PogoInTheWoods]

Sounds like the crank is too short if I'm understanding the explanation correctly.

 

[ncrile]

where the flywheel is furthest on the crank the crank measures 13.5 mm and is about 5 cm from case. That’s the inner mark on the crank. From the case to the threads is about 2.5 cm. I always press the bearings into the cases until they bottom out. Then I press the crank into one side, put the gasket on and pull the case together with long screws. Always the crank is tight and does not spin freely because it’s under pressure. To release the pressure I put the spider on the clutch side flush and tap it with a hammer. I do the same on the flywheel side. This relieves the pressure, centers the crank and it spins sweetly. I’ve never used aftermarket crank. I have a box of oem if you want one. Are you using the same flywheel that came with the case. Shouldn’t matter but might. 075,... is it a roller case (points) or electronic?

Thanks for your help. It has an electronic ignition (no points) but a different case (fewer mounts for the points).




After some thought. I'm wondering if (in my excitement to put it together) I either didn't fully seat the bearings or seated one of them at an angle. Assuming the crank is the correct dimensions (and I'm not sure it is), I might split the case, pull the crank, and double check that the bearings are seated? I don't own a press so I put them in by freezing the bearings, heating the case. Hammer and socket on the outside race. Would that make sense? If that doesn't work, I may take you up on your offer (thank you, BTW).