028 AV Super - Scored Cylinder

[Yellowbeard]

Walked into my local Stihl dealer today to have a key made and they had an 028 with a scored piston in the back. I use my dad's old 028WB (made in West Germany) as my light saw and have always loved it. They said I could have it for a 20 dollar bill so I brought it home, for parts if nothing else.

However, I just moved into a house with a garage and am OK, at least, as a mechanic. Anyone know where I could get a new old stock cylinder for it? I suppose I would need rings as well.

If I can't get Stihl parts, what should I get if I wanted to go down this road?

Thanks in advance!

 

[HarleyT]

If you get a complete cylinder kit, it would have new piston and rings.

 

[HarleyT]

But chances are, the cylinder can be saved, and you would just need a piston kit.

 

[Yellowbeard]

Fair point. I see a bunch of used pistons and cylinders on ebay for $75... Maybe that would work out? If I got the saw running for under $100 all in I'd feel pretty good.

 

[Yellowbeard]

But chances are, the cylinder can be saved, and you would just need a piston kit.

Really? Interesting. I suppose I should get a hold of Randy and see what he would charge me to go through it.

 

[HarleyT]

Pull the jug and take a pic before buying anything!

 

[HarleyT]

I should get a hold of Randy

You have got to be carefull where you grip.....

 

[Yellowbeard]

You have got to be carefull where you grip.....

Indeed. Although I sent him an 084 and he rebuilt/ported it. I could not believe how awesome that thing was. After I made my first slab cut I just had to put it down and call him to tell him how awesome it was. Will post video of it at some point.

 

[Yellowbeard]

When I get a chance I'll take it apart and post some pics. Thanks!

 

[Yellowbeard]

Well, I finally took this apart. I'm not sure what scoring is supposed to look like (this is a learning experience for me) but this doesn't look particularly scored to me. However, now that I have it apart, I am regretting not having cleaned it more. How do I get out of the mess I am currently in?

Clearly I need a new gasket at the very least.

The rest of the saw seems to be in really good shape. I would love to be able to get it running and use it if possible. My other 028 is my dad's old saw and reads "made in West Germany" somewhere on it. I feel like I need something that's at least slightly younger.

Lastly, since I have it apart, is there a big bore kit I can put on it? What am I getting into cost wise on something like that? I know a cylinder/piston kit is around a hundred bucks (more or less) but would I need a new carb or anything?

Frankly, if I can just have this cylinder polished, put in new rings, and put it back together and have a solid saw for around 50 bucks then I would count myself lucky.

 

[HarleyT]

Is Batman working on your saw?

 

[HarleyT]

Take a closer pic of #2. A new piston/rings should be all you need. The scoring/damage is usually right at the exhaust port.

 

[Yellowbeard]

"I'm batman."

I love these gloves. Been using them whenever I do any kind of mechanical work for years. They save me tons of cuts and scrapes and constant grease under the nails. I know that makes me not a real man, but, at a certain point, I just get sick of scrubbing. Also good for robbing banks. Wait. Wasn't supposed to say that...

Anyway, here are some photos. If I can get away with nothing more than piston and rings then I am going to be really stoked. Actually, now that I am looking at these pictures, I can clearly see where the piston is scored. I wonder what did that. What's typical?

Also, I see that the OEM piston is about 85 bucks whereas something like a meteor is in the $30 range. What piston/ring kit should I get? Advice appreciated.

Thanks for the help!

 

[JonCraig]

The "scoring" is where the piston/cylinder get hot enough that the aluminum piston melts and transfers onto the (cooler & harder) cylinder liner. The piston is done for; I've used multiple Meteor 028S pistons (3 I believe) with no issues. To remove the transfer from the cylinder, you'll want to "wet sand" with WD40 and small strips of wet/dry 400 grit sandpaper. The good stuff. Then you'll think that's taking too long, and you'll use a scotch brite pad. Then try strips somehow rigged into a Dremel. Then think the sandpaper by hand was faster. Then back to dremel, etc. etc. And finally you'll discover that you've sanded off all the transfer. At least that's how it works for me.

The cylinder plating is harder than you think.

an 028 is also a fantastic saw to do a full teardown to learn on. Bearings can be had for not too terrible of a price. Crank seals are still available. Search this site on how to measure squish. My 028S with a gasket delete runs noticeably stronger than the one without. Not exactly a scientific test, but you know.

Fun project.

 

[67L36Driver]

Just going by the slight dome on the piston, I’d say that is an 028 Super. So, it’s already the ‘big bore’ version. 46mm

Yes, a Meteor piston w/rings is the best go.
[emoji106]

 

[Yellowbeard]

The "scoring" is where the piston/cylinder get hot enough that the aluminum piston melts and transfers onto the (cooler & harder) cylinder liner. The piston is done for; I've used multiple Meteor 028S pistons (3 I believe) with no issues. To remove the transfer from the cylinder, you'll want to "wet sand" with WD40 and small strips of wet/dry 400 grit sandpaper. The good stuff. Then you'll think that's taking too long, and you'll use a scotch brite pad. Then try strips somehow rigged into a Dremel. Then think the sandpaper by hand was faster. Then back to dremel, etc. etc. And finally you'll discover that you've sanded off all the transfer. At least that's how it works for me.

The cylinder plating is harder than you think.

an 028 is also a fantastic saw to do a full teardown to learn on. Bearings can be had for not too terrible of a price. Crank seals are still available. Search this site on how to measure squish. My 028S with a gasket delete runs noticeably stronger than the one without. Not exactly a scientific test, but you know.

Fun project.

OK, so I am sanding out the aluminum transfer from the piston to the inside of the cylinder wall - I get that. How do I know when I am finished? Just feel? Also, do I need to worry about anywhere else on the inside of the cylinder?

As for the rest: This saw is in GREAT shape compared with my other saw. So, for now, my plan is to see if I can get it running. Then, maybe what I should do is rebuild Dad's old saw, then I can go back to this one.

I LOVE dad's saw, and it's just a plain old 028 WB. I am assuming this will be a bit more power.

Also, thanks - you just taught me what "squish" is. I get it now. Now I have to decide if I want to try and increase compression at all (using a number of techniques I have just seen) or just run it stock for a while (which, I am sure, will be fairly satisfying on its own).

Thanks!

 

[Yellowbeard]

Just going by the slight dome on the piston, I’d say that is an 028 Super. So, it’s already the ‘big bore’ version. 46mm

Yes, a Meteor piston w/rings is the best go.
[emoji106]

Thanks for the info! Yeah. If I can get out of this for $50 bucks and a running saw then I am going to be a happy camper.

 

[JonCraig]

You’ll know when you have it removed when you can’t see it anymore (for lighter/not as bad transfer) or (for the worst parts) when you have made a whole hell of a lot of progress, but there’s just these 1 or two lines that won’t go away. When you can’t feel those with a fingernail, you’re good. Don’t rush it. When I get pissed off at a cylinder, I try to set it aside and go do some yard work or something. Often when I come back to it, it seems less of a PITA.

My $0.02

 

[Yellowbeard]

You’ll know when you have it removed when you can’t see it anymore (for lighter/not as bad transfer) or (for the worst parts) when you have made a whole hell of a lot of progress, but there’s just these 1 or two lines that won’t go away. When you can’t feel those with a fingernail, you’re good. Don’t rush it. When I get pissed off at a cylinder, I try to set it aside and go do some yard work or something. Often when I come back to it, it seems less of a PITA.

My $0.02

Worth far more than $0.02, I am quite sure. Thank you!