How bad is this scoring?

[stumpdaddykane]

Hey y'all,

Just picked up a used MS460.i had it shipped so wasnt able to check out the jug, but I just popped the muffler cover off and saw this. Some light scoring on the Piston and what looks more like pitting on the cylinder wall close to the intake. How bad is it? Worth contacting the seller as I was assured everything was in tip top shape? Thanks y'all!

 

[Bob Hedgecutter]

Only way you are going to tell how bad things really are in there is to open it up and get a proper look.
If you can reach through the exhaust port (with a long straight pic tool) and see if those suspect pits are holes through the plating- I would be a bit miffed- but it could be genuine the seller never looked in there or was aware of them.
Looking at the exhaust side of the piston and interior of the port- I would hazard a guess they are carbon scores.

 

[stumpdaddykane]

Only way you are going to tell how bad things really are in there is to open it up and get a proper look.
If you can reach through the exhaust port (with a long straight pic tool) and see if those suspect pits are holes through the plating- I would be a bit miffed- but it could be genuine the seller never looked in there or was aware of them.
Looking at the exhaust side of the piston and interior of the port- I would hazard a guess they are carbon scores.

Provided they are carbon scores and that isn't a hole in the plating, I'm guessing just running better quality oil will fix it up?

Only way you are going to tell how bad things really are in there is to open it up and get a proper look.
If you can reach through the exhaust port (with a long straight pic tool) and see if those suspect pits are holes through the plating- I would be a bit miffed- but it could be genuine the seller never looked in there or was aware of them.
Looking at the exhaust side of the piston and interior of the port- I would hazard a guess they are carbon scores.

Well I dug into her and yup a few spots on that intake side are worn into the plating. Damn I was excited about this saw. Anything that can be done? If it still runs ok is it just a matter of time before she falls?

 

[94 wrangler]

I'll assume you bought the saw on eBay since you said, you had it shipped. If so, IMHO and experience with eBay saws, lower your expectation levels by at least 50%. That scoring probably won't be enough compression loss that it won't start but its certainly not going to give you the performance that it should. Did you check the compression?

 

[huskihl]

You can’t really tell what things are on the opposite side by looking through the exhaust port. Cylinders are almost always streaky looking on the other side from the light you’re shining in and oil, even brand new ones. The pits or holes aren’t optimal but many cylinders have tiny holes in the plating like that and run fine. You would need to remove the cylinder and have a look at the piston to get a better idea

 

[pioneerguy600]

I don`t know about the rest of you but I cannot see any factory machining marks on the piston indicating that the engine has high hours of operation on it. That does not mean it is badly scored but more just wear and carbon streaks on both the cylinder and piston, the compression may still be high enough to start and run but I would suspect that the engine is close to needing a rebuild and not producing anywhere near it top potential. Running more oil in the mix helps a bit to keep high hour engines running a bit better/longer.

 

[Mad Professor]

Provided they are carbon scores and that isn't a hole in the plating, I'm guessing just running better quality oil will fix it up?

Well I dug into her and yup a few spots on that intake side are worn into the plating. Damn I was excited about this saw. Anything that can be done? If it still runs ok is it just a matter of time before she falls?

How about some clear pictures of the cylinder, maybe after a little preliminary clean up.

 

[Lightning Performance]

How about you send it to someone or have friend who knows what they are looking at inspect it for you?

 

[stumpdaddykane]

I'll assume you bought the saw on eBay since you said, you had it shipped. If so, IMHO and experience with eBay saws, lower your expectation levels by at least 50%. That scoring probably won't be enough compression loss that it won't start but its certainly not going to give you the performance that it should. Did you check the compression?

Yeah I got it off a Stihl chainsaw Facebook page. I reached out to the seller and he was really cool about it. Apologized for it and got a line on a decent shape OEM cylinder and potentially a piston for me. He's gonna send then along for no charge.

I don't have a way to test compression, but I figure it should pull somewhere in the middle between my 064 and 400. Definitely feels like a lighter pull then the 400.

 

[stumpdaddykane]

How about some clear pictures of the cylinder, maybe after a little preliminary clean up.

Yeah can do that. Seller is sending along a different cylinder and maybe piston, so I can get a better look then.

 

[stumpdaddykane]

How about you send it to someone or have friend who knows what they are looking at inspect it for you?

Yeah that would be nice, but unfortunately I'm the most knowledgeable small engine guy of my buddies and that's obviously not saying much haha. Looks like the seller is sending along a different cylinder though.

 

[Lightning Performance]

Yeah can do that. Seller is sending along a different cylinder and maybe piston, so I can get a better look then.

Rings and a cylinder. Keep those in sets or buy new rings.