Is this cylinder beat?

[chevybob]

Pictures make it look worse but what do you all think? Saw ran strong but I got a new piston and rings anyway. Would honing clean that up?

 

[DexterDay]

Being linear with the cylinder? Some would use it. Because the ring won't catch it. Other will say to trash it.

What happened? A ring retaining pin let go? Or ring broke?

 

[50blues]

If its for you, I would run it. You wont loose much compression.

 

[Adirondackstihl]

Would honing clean that up?

No

Just de-glaze the cylinder with some emery paper and run that sumb!tch

 

[chevybob]

Ya I took some 2000 grit to it and cleaned it up nice there wasn't any scratches or serious glazing. The walls look like a mirror which is good in my book. Ya I assume a ring pin let go cus I didn't see it when I pulled the jug off.

 

[Adirondackstihl]

400-600 grit

 

[nmurph]

It won't hurt a thing.

The compression will build over time as the groove fills with carbon. This might be a good case for dino oil as opposed to synthetic.

 

[jughead500]

Yeap Run it.If it finishes getting trashed what have you Lost? Nothing Just Gained some extra use.

 

[Stormy]

400-600 grit

Would this be to leave honing marks (@45°) to help trap oil? Read that you don't want a mirror finish for this reason. Just tryin to learn.

 

[Adirondackstihl]

Would this be to leave honing marks (@45°) to help trap oil? Read that you don't want a mirror finish for this reason. Just tryin to learn.

Yes
Will help rings seat faster as well

 

[Jacob J.]

It won't hurt a thing.

The compression will build over time as the groove fills with carbon. This might be a good case for dino oil as opposed to synthetic.

Yep- I took apart a good running stock 394 a couple months ago because the main bearings were shot. The cylinder had a nice score mark from one upper transfer all the way to the squish band.
The owner had cleaned up the jug and put a new OEM piston and rings in it and ran it for years. Now you can hardly even feel the score mark. I wouldn't put it on a customer's saw but I'd happily
run it on one of my own.

 

[chevybob]

Thanks for the help everyone. So I should use 400-600 grit instead of the finer stuff? I knew about the cross hatch pattern but didn't realize it was to help oil better.

 

[SawTroll]

It won't hurt a thing.

The compression will build over time as the groove fills with carbon. This might be a good case for dino oil as opposed to synthetic.

I don't really see any damage at al - am I getting blind?

 

[nmurph]

I don't really see any damage at al - am I getting blind?

Must be!! I bet your Mother warned you about doing that when you were alone!!!

Yes, there's single score from the top of the exhuast to the top of the cylinder. It looks to be pretty deep, but it also looks to be narrow and the only one.

 

[Stormy]

Must be!! I bet your Mother warned you about doing that when you were alone!!!

Yes, there's single score from the top of the exhuast to the top of the cylinder. It looks to be pretty deep, but it also looks to be narrow and the only one.

Lol. Either that or yer readin too much as per yer avatar. Sure that isnt actually a picture book? I see a straight dark line but wondered whether it passed the finger nail test I keep hearin about.

 

[nmurph]

The "Nail Test" only pertains to metal standing proud. Scoring is evaluated differently- location, number, depth, etc...

 

[anlrolfe]

Is it me or does it look cracked or just camera reflection?

could it be bad casting or stress cracks??

 

[Stormy]

The "Nail Test" only pertains to metal standing proud. Scoring is evaluated differently- location, number, depth, etc...

Thanks! That's worth months of future learnin, at least. Probly more. As long as we're speculating, might there not be two other lines adjacent (going ccw), and might not that entire area already be fillin in with carbon depositing?

 

[SawTroll]

Must be!! I bet your Mother warned you about doing that when you were alone!!!

Yes, there's single score from the top of the exhuast to the top of the cylinder. It looks to be pretty deep, but it also looks to be narrow and the only one.

OK - I saw it all the time then - but "misread" it, thinking it was a string of metal pointing at the suspect area.....

 

[chevybob]

Must be the camera I took a close look and there doesn't seem to be any cracking at all.

Is it me or does it look cracked or just camera reflection?

could it be bad casting or stress cracks??

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