Chrome bore cylinder questions

[Mark71gtx]

I like 020AV Stihls. I have a few that don't run so well anymore. I tore one down that would pop, but wouldn't run. All of the machining marks were off if the piston, just smooth as it could be. I was looking at the cylinder and it looked like it could use some cleaning. I hit it with scotchbrite and it still does not look great to me. Is the plating too worn? Should it look like this? I have cleaned several cylinders before, but never a chrome one. How does this look to you? There was zero transfer or scoring in the cylinder. It just isn't bright like I am used to seeing.

 

[Red97]

Might be a little wore, but can't see any streaks of al showing through. How did the rings look? Probably a fresh set it would be good to go.

 

[Mark71gtx]

Rings looked okay and still had spring in them. The pistons were smooth as glass though. No machine markings left on them. I assume that would cause too much slop and would interfere with proper performance. I have two new pistons on the way already.

 

[Mark71gtx]

Does this look like wear to you guys, or just crappy plating around these ports?

 

[Mark71gtx]

 

[Red97]

Those look like the bevel is plum wore off.. but odd no transfer streaks.

You have a new ring to put in the bore and check the end gap?

 

[Mark71gtx]

I have some NOS Stihl rings. I will give it a check. I have two cylinders in front of me.

 

[Adirondackstihl]

That's a wide bevel
Where the rings never contacted the plating & where the factory hone never touched

 

[Red97]

That's a wide bevel
Where the rings never contacted the plating & where the factory hone never touched

Think you are correct,

Appears to be an as cast bevel, vs the ground ones I'm used to.

 

[Mark71gtx]

Both cylinders read .012 They are both KS cylinders. I just pulled another cylinder out of the parts box that is a Mahle. It has a lot of transfer in it though. The other KS cylinder looks better around the ports than the one I took pictures of, but the rest of the bore is not as nice and shiny as the one with the rough edged ports. Wondering which would be best to use.

 

[Mark71gtx]

The saw with the Mahle looks like it was having a hard time breathing lol...

 

[Red97]

Both cylinders read .012 They are both KS cylinders. I just pulled another cylinder out of the parts box that is a Mahle. It has a lot of transfer in it though. The other KS cylinder looks better around the ports than the one I took pictures of, but the rest of the bore is not as nice and shiny as the one with the rough edged ports. Wondering which would be best to use.

That gap seems fine, I'm sure either would work well with a new ring.

 

[Mark71gtx]

Thanks. It will be getting a new piston too. Machine marks are gone.