Stihl 08S problem

dustytools · Oct 17, 2006

Hi, I hope someone is familiar with my antique saw. I have an old Stihl 08S. Recently I was doing some light duty milling and my saw died, similar to the way it does when it runs out of gas. After all of the usual checks I still couldnt get it to start. Just as I was ready to call it quits for the day I noticed a perfectly round hole the size of a U.S. penny in the right side of the head about half way up. It looks like some kind of knock-out for a compression release or something. I stuck a penny in the hole ,held it in place with my finger and the saw started on the first pull. Ran fine till it got too hot to hold onto, as soon as I moved my finger the penny blew out and the saw died. This hole doesnt have any threads to recieve anything, I guess the cover that used to be over it blew out as I was milling. Can anyone give me any suggestions as how to remedy this problem. It is still a very good saw and I would hate to have to retire it or do a major overhaul on it if I dont have to. Thanks.

retoocs555 · Oct 17, 2006

I just had a look at the cylinder on an 08 here and I see exactly the place you're talking about.

I'm not sure what its purpose is.

Maybe you could tap the hole out and put a plug in it?

stihltech · Oct 17, 2006

08

Sounds like an original of the line. I believe these plugs were used to port the cylinder on early models.
I have epoxied a couple back in with good results. Use the highest temp epoxy you can find.

Sprig · Oct 17, 2006

My faithful old 08s sits in pieces right now, it is my beast of burden and is needing some attention(ignition wire), a real work-horse of a saw if ever there was. Though I haven't looked-see at what you're talking about my guess is that it is/was an afterthought type thing for a decompression valve. If there's enough meat to tap it follw the above ^^^ suggestion and tap and plug it, make sure that the plug does not extend into the cylinder (and maybe buff it nicely). My saw is over 30 years old, I can stihl read the numbers on the pistonhead

Run at 20-25:1 they will last forever, are easy (relatively) to work on, have tons of torque and heart. Mine is running a new 21" blade Stihl blade (had to modify the oiling holes tho and not an 18" because I'm tall and its easier on the ol' back) and (Oregon) chisel tooth 3/8ths chain sharpened at 35x5 degees. They are a tad slow (around 7000-7500 rpm), and heavy for smaller folks, but treated right will out last most anything, there is a reason they were sold as an industrial saw. As far as I can remember they were still making parts for them in Brazil until a few years ago (I stand to be corrected on that tho) and there are lots of basket cases out there if you ask around, has ta be they were produced for nearly 30yrs from '65 to the early 90's. I'd probably look into replacing the cylinder and do the rings while you're at it. Slagged as they have been I've rarely had a problem with mine and until I pulled it apart (I have a thread here somewhere on being zapped, it was the origional ign. wire, quite pooched) it started within 1-2 pulls no matter what the weather. Setting the needle valves on the Walbros can be a bit of a chore (at least it is fer me when I have mucked with them) but once dialed in its easy. My opinion.

dustytools · Oct 18, 2006

Actually the original fix, which lasted for about 2 to 3 hrs of sawing, was a penny that was held in place with epoxy seemed to be perfect till it blew out Sunday while I was just getting ready to mill a small oak. I think that I will try it again with some high-temp epoxy this time. Thanks for the replies.

Sprig · Oct 18, 2006

Np, btw mine does not have that wonderful feature on it though there looks like a place on the lower right where it could have been located once but maybe re-casting has hidden it? Dunno. My thoughts on milling with this saw are these: Though they have torque and heart they are after all only just over 3.4hp and running at 7000max rpm would be okay for pines, firs, semi-hardwoods etc about 10" maximum, sharp chain, no big pushing on it ( boggin' it down), sort of (reality check small) small for any serious milling unless its a throw-away machine

cry

. I love my little antique beast and wouldn't think of subjecting it to hard labour like that, but thats just me. Stihl think a tap and plug would work. In afterthought I thought the idea (a previous post) that it was origionally an access for porting was a great thought but I really have no idea so I stick with my opinion that it was for a decomp. valve that never was (like you'd ever need one on a teeny saw like this (jk, jk)). Who the heck knows? I'd like to know more so common all you old-saw-runners getcher heads out.

dustytools · Oct 19, 2006

Youre exactly right on the slow speeds. I just mill cedars and small diameter hardwoods with it. I dont crowd it so yes it is slow but very tough on the torque end. I have a 395 that Im gonna start using on my bigger milling projects. Thanks for the input.