My Stihl 08S Restoration

[ozziechainsaw]

Hi Guys,

This is my first full restoration project and I have decided to go with one of my favorite saws, the Stihl 08S. This is a earlier 08S with no chain break and the "Stihl Saw" logo .

Looking forward to everyone's thoughts and opinions, but please be gentle it's my first...lol

This I did compression test before I started to remove anything and it has 150 psi compression cold. So at least I know the cylinder is good before I take it fully apart. I will hopefully resplacing all the seals and bearings, including the piston and ring assembly.

You can see by the photo's it is in fairly good condition before i even start, but after I started removing the outer cover and clutch assembly you can see that something as sometime previously has gone bad in a big way in the clutch area. There is cuts into the magnesium and 1 that has gone right through at the top. I will have to do something about that cut before reassembly.

Cheers

Justin

 

[L34]

Looks like clutch drum wear.

 

[ozziechainsaw]

So I have most of it apart. Now it's time for the cases to come apart.
Such as shame I had to remove the spark plug boot from the lead, would of made things so my easier down the track when putting it all back together.
Everything looks to be original including the cylinder, the piston is 47mm. The cylinder has no marks on it , just the normal wear marks for something of it's age. I will give the cylindera slight hone before everything goes back together.
Cheers

Justin

 

[ozziechainsaw]

So i have all the screws out , including the 2 dowels and i still cannot get the cases split. Anyone have any ideas ? Is there something i'm missing ?

 

[scallywag]

Has this damage cut through to the gallery?

 

[StihlSolo]

Yes, at blue circled area. Can't tell if cut broke through.

 

[scallywag]

Looks like clutch drum wear.

Must be the wrong drum or missing a spacer or something?...I'm surprised it doesn't show signs of an air leak.

 

[ozziechainsaw]

Hi Mate,

yep it has gone through the case, see attached photo. This saw was not actually started. It did run however on some spray and I compression tested it as well.
I was hoping that I could use something to fill the space. Not sure what I could use yet. Maybe some devcon anyone else have idea's on what I could use to fill the space successfully and not get any air leaks ?

Justin

 

[ozziechainsaw]

Also anyone got any ideas on how to seperate the cases ? All the screws and both dowels have been removed but it still will not budge.
Just worried I am damage something if i use too much force.

Justin

 

[scallywag]

See post #7 here....... https://www.arboristsite.com/community/threads/stihl-08s-workshop-manual.185632/

Thanks to @HarleyT

 

[ozziechainsaw]

yeah I have that. Not real helpful in seperating cases.
But thank u for the offer.
I'm just worried that if i use too much force I will break something.

Justin

 

[scallywag]

If you're sure you've removed all the screws/bolts/dowel pins, using a heat gun or hair dryer thoroughly heat the cases and let them cool a few times, at the same time tapping them with a soft hammer.

 

[ozziechainsaw]

So with a little extra force it decided to seperate. Bearings were a little bit noisy, probably could of left them in but if I'm doing a restoration i had better do it correctly.
So after pulling the cases apart you can see the previous owner has what I would assum dropped the saw and damaged the casing. He has plugged it very well and it was holding fuel.

What I am concerned about is once I sand blast it all will it still hold or should I just remove what he did, clean it correctly and somehow fix it ? Not sure about this. Opinions anyone ? And what could I use to repair it ?
Also i got new/used sanding cabinet today and decided to have a play with it quickly on the outside of the cylinder. So as everyone can see it has been replaced before with a Mahle cylinder and I'm assuming a piston as well. When I get more time I will look at the piston as well.

 

[scallywag]

it has been replaced before with a Mahle cylinder and I'm assuming a piston as well.

The Mahle piston & cylinder is OEM.

 

[scallywag]

Also i got new/used sanding cabinet today and decided to have a play with it

If you're going to clean the cases with it, say well away from any mating surfaces.

 

[ozziechainsaw]

So Mahle is factory OEM Stihl ?

So what about the fuel tank repair ? What should I do there ????

What's everyone's opinion ?

 

[ozziechainsaw]

So I sand blasted the hole in the case to have a better look. And I am sure it can been sealed. I will just have to work out what's going to be the best sealant.

Decided to clean all the gasket surfaces today and you can see by the photo, 1 of the cases where they join has the same numbers stamped into the case as what's on the outside. I never knew that. At least it proves that this saw isn't made out bits and pieces.

Also I cleaned the area where the fuel tank has been repaired by the previous owner. He actually did a good job of it.
Just not sure if i should remove it or just leave it alone. It was holding fuel . So i'm still not sure.

 

[StihlSolo]

I would say cases should be replaced as a set. Your original cases have two strikes again them. First the cuts through the PTO webbing and that cut through the transfer. Then the gas tank repair. Looks light previous repairer used a plate riveted and glued to case, then covered it with something. Case being one metal and plate & rivets being another type of metal., something's eventually going to leak. Easier to find a donor set of cases.

Once did an 08s where original owner had left saw on a damp floor. Bottom was holely & rotted. Got donor saw for its crankcase, but saw's crankshaft and bearings were rusty, seals hardened. Second donor saw cases worked just fine, replaced seals and bearings anyway, worked fine as a 08s then eventually made it into a 60cc TS350. Perserverance...and I still use my chop saw.

 

[ozziechainsaw]

Yeah it's starting to look that way. I would really love to keep it all original but if i put that back together and it leaks I will be very upset.
It's starting to make me stress.

 

[Bob Hedgecutter]

Yeah it's starting to look that way. I would really love to keep it all original but if i put that back together and it leaks I will be very upset.
It's starting to make me stress.

How easy is it to find an 08S donor saw in Aussie?
Or at least one that has good cases but the rest trashed enough that you not need to pay collector value to secure it?