Is this scored?

[Rykirk]

I think I already know the answer. Just confirming. Is that scoring in the cylinder? And im guessing i need a new cylinder. First time doing a rebuild.
I already knew the piston rings broke before hand.

Also.question. is it normal for the camshaft arm to have that much play in between. I hope I don't need to break down the guts of the beast

 

[old guy]

I don't see any transfer from the piston to the cyl., and it looks like the rings are free in the grooves.
It does look like some carbon or something went thru it, I would mke sure the rings are free then rub up the cyl with red or green 3m pads, but I am not there so can't see everything.

 

[Gord404]

and the crankshaft and rod do have play side to side as long a it is not up and down- the piston centers it when put together.

 

[Rykirk]

here's a couple more pics. So are you saying if there are no cut grooved lines inside the cylinder it should be ok to use?

 

[Gord404]

if you cant feel anything wit your fingernail- no groves, I would still clean it up a bit before you put it together - no leftover piston anywhere is important

 

[James Sawyer]

Can you clarify your comment regarding the Crankshaft play? How's the crank rotate is it smooth and is there play in crank bearing UP/down on the PTO or Flywheel end of the crank. I think you can clean up the cylinder at least try with some 600-grit sandpaper and scotch Brite. You might be surprised. A OEM piston is ~$80 and AM $40 (meteor is my suggestion)
Next question do you know what failed that caused the scoring. I guess what I'm getting at depending on what failed is it worth a total rebuild and do you have the skills and tools to split the case and replace the bearings. The cylinder cleanup and new piston is not much trouble, new bearing and seals for some is a little more involved than some want to do? I think you could save that cylinder it may not be perfect, but you probably be fine. What saw is it? You might be able to get it running for less than $100 if you go AM (new piston (Meteor), Seals & gasket (Hyway), Impulse and fuel line & filter. If it a husky the crank bearing are cheap but Stihl the PTO bearing is not $35.

 

[Rykirk]

Can you clarify your comment regarding the Crankshaft play? How's the crank rotate is it smooth and is there play in crank bearing UP/down on the PTO or Flywheel end of the crank. I think you can clean up the cylinder at least try with some 600-grit sandpaper and scotch Brite. You might be surprised. A OEM piston is ~$80 and AM $40 (meteor is my suggestion)
Next question do you know what failed that caused the scoring. I guess what I'm getting at depending on what failed is it worth a total rebuild and do you have the skills and tools to split the case and replace the bearings. The cylinder cleanup and new piston is not much trouble, new bearing and seals for some is a little more involved than some want to do? I think you could save that cylinder it may not be perfect, but you probably be fine. What saw is it? You might be able to get it running for less than $100 if you go AM (new piston (Meteor), Seals & gasket (Hyway), Impulse and fuel line & filter. If it a husky the crank bearing are cheap but Stihl the PTO bearing is not $35.

It's a Stihl 066.
As per crank shaft play I meant it moves from left to right by a fraction. But another member said that is normal.
Through closer inspection last night the cylinder looks pretty decent and smooth but I did find a bit of scoring under the exhaust port. I saw some vids last night and people are saying it's no prob to, like you said get Scotch brite and sand paper, and only focus on the etch.
Seems like there is a big carbon build up at the top of the cylinder. Should that be cleaned? Also, Should I scotch brite the carbon lines going down the sides of the cylinder.
I'm thinking of just blowing out the crank shaft chamber before reassembly. I see ppl putting some type of oil on the bearings, not sure what to use

 

[Rykirk]

 

[Mad Professor]

Mix is good to rinse out the bottom end.

What are the fuzzy things on the top of the piston? Wood debris or metal? Post #1 pic #3

 

[Rykirk]

Mix is good to rinse out the bottom end.

What are the fuzzy things on the top of the piston? Wood debris or metal? Post #1 pic #3

What mix are you thinking. Like a engine degreaser

The white bits are from the crappy rope I used to stop the piston when I was trying to remove the flywheel. Should have used a nylon rope.
And I couldn't take flywheel off. It's like seized on there. Prob need a puller

 

[Mad Professor]

What mix are you thinking. Like a engine degreaser

The white bits are from the crappy rope I used to stop the piston when I was trying to remove the flywheel. Should have used a nylon rope.
And I couldn't take flywheel off. It's like seized on there. Prob need a puller

pre-mix. Washes stuff out and oils/prevents rust.

I use soft nylon rope, and burn the ends so no frays.

 

[Gord404]

the crankshaft it's self should have no play any direction - the con rod has a gap on either side

 

[James Sawyer]

the crankshaft it's self should have no play any direction - the con rod has a gap on either side

hope the bearings didn't spin in the case... if so probably not worth putting money into that saw if they did. That's not good... wow if that is the case!

 

[Gord404]

hard to tell without more info- short vidio clip would help- did up a 660 a couple of weeks ago - pto side lost its cage- if you still have the bearings you can line them up with grease in between to hold them in place and push the crank out and remove the bearing, but like I said we need more specific info

 

[thompsoncustom]

It's a Stihl 066.
As per crank shaft play I meant it moves from left to right by a fraction. But another member said that is normal.
Through closer inspection last night the cylinder looks pretty decent and smooth but I did find a bit of scoring under the exhaust port. I saw some vids last night and people are saying it's no prob to, like you said get Scotch brite and sand paper, and only focus on the etch.
Seems like there is a big carbon build up at the top of the cylinder. Should that be cleaned? Also, Should I scotch brite the carbon lines going down the sides of the cylinder.
I'm thinking of just blowing out the crank shaft chamber before reassembly. I see ppl putting some type of oil on the bearings, not sure what to use

Here is a good way to hone the cylinder with a scotch brite pad, first part with the sand paper is for removing aluminum transfer.

 

[Rykirk]

the crankshaft it's self should have no play any direction - the con rod has a gap on either side

Aw man i sure hope it's not a bad scenario. Hopefully this gif helps.

 

[Rykirk]

If I do need to get in that crank shift chamber I would need special tools like a flywheel puller. I saw a video last night of a guy rebuilding a 660 crank shift. He was using special tools to installing the bearings and removing the shaft etc. If they don't go in perfectly it can cause issues when running the saw

 

[LuckyRookie]

The movement of the connecting rod you shared the video of is totally normal. I've never seen a saw where the connecting rod was "pinned" to an exact location on the crank shaft.

 

[Rykirk]

The movement of the connecting rod you shared the video of is totally normal. I've never seen a saw where the connecting rod was "pinned" to an exact location on the crank shaft.

That puts me at ease. I haven't worked on an engine like this since in 30 years, mechanic class in grade 11. We all had to tear apart our dad's chainsaws straight down to the crankshaft. Clean them and rebuild them.