Made a decision

[Whiskerfish]

Yea it sucks, but because of it I was able to pickup a really nice complete bike for 400 bucks. The deeper I got into this thing the nicer I realized it was. When I took off the removable frame section and shook it there is Zero rust inside floating around. Those are getting rare so that will be going on a shelf!

[Whiskerfish]

Well this sucks, I was not expecting this. When I first saw it I thought it was a crack but it does not extend out to the end of the sleeve so I guess it is just a scratch. I can catch my finger nail slightly the full length of it. That first picture shows something on the piston top in line with the scratch but it wiped off.

There is a small dimple in the head next to the plug hole. No other damage and the compression on this jug was good.

Recommendations?

P6131341.JPG

P6131347.JPG

P6131353.JPG

[Rat]

Looks like a scratch from here. Doesn't seem to go through the thickness of the wall ?

Wait a minute .... YOU'RE asking ME ??

Gord (running for the beer fridge) Jones

[Whiskerfish]

Looks like a scratch from here. Doesn't seem to go through the thickness of the wall ?

Wait a minute .... YOU'RE asking ME ??

Gord (running for the beer fridge) Jones

Your the Supervisor so supervise

[Whiskerfish]

Almost 4 pm and I have a fresh bottle of Seagrams that needs busted into. Might be time to do some serious pondering

[Rat]

Now THAT I can help with ....

Gord

[Track T 2411]

Well, the debris had to be significant enough to dig into the cylinder wall. One scratch isn't going to affect compression enough to matter, it's less than a ring gap. My concerns would be is something still lodged in a ring to cause continued wear and would the scratch cause issues with the rings' movement around the piston, or possibly a broken oil ring. Can you tell if the scratch goes all the way to the rings at BDC? A very light hone would ensure that there's no ridge associated with the scratch.

[rcmatt007]

sure looks like something rode up and down that jug

[Whiskerfish]

SNIP would the scratch cause issues with the rings' movement around the piston, or possibly a broken oil ring. SNIP

That to me is the issue/question. I can easily accept the minuet loss of compression but I am getting ready to throw well over a hundred bucks worth of seals and such at this engine and do not want to waste my money. I can not see an end to it at BDC and it does seem slightly deeper the further in you go. This is # 3 so the crank would have to come out to inspect it properly. I do have the gaskets/stuff on hand to split it but that is just more money.

sure looks like something rode up and down that jug

Yea I am fairly certain a foreign object of some kind got in there.


On my second 7 & 7 but might have to have more than a few drinks tonight to get to the decision point of this one.




.

[Old Fogey]

Well, the debris had to be significant enough to dig into the cylinder wall. One scratch isn't going to affect compression enough to matter, it's less than a ring gap. My concerns would be is something still lodged in a ring to cause continued wear and would the scratch cause issues with the rings' movement around the piston, or possibly a broken oil ring. Can you tell if the scratch goes all the way to the rings at BDC? A very light hone would ensure that there's no ridge associated with the scratch.

Yes, the scratch can be ignored, but the cause can't be. Just the kind of mark a broken ring might make if it's not been run much with it broken.

[robin1731]

The dimple in the head is normal. Look at some others you have.

.

[terry_208]

Something I'm not understanding. The pictures seem to show the scratch extending beyond the mark of the top ring in the bore. If that was the case, I would think you would be able to at least see the bottom of the scratch. Am I not seeing what I think I'm seeing?

I hope you're enjoying your adult beverage!

[rcmatt007]

scratch, scotch, heck I just wear out, but a little vodka and orange helps

[Old Fogey]

The dimple in the head is normal. Look at some others you have. .

I was looking at the mark in the red circle.
The dimple in the blue circle is a standard casting mark on them all.

P6131353 (Medium).JPG

[Old Fogey]

Something I'm not understanding. The pictures seem to show the scratch extending beyond the mark of the top ring in the bore. If that was the case, I would think you would be able to at least see the bottom of the scratch. Am I not seeing what I think I'm seeing?

I hope you're enjoying your adult beverage!

I've just blown that picture right up and enhanced it. The scratch extends right to the piston top land and stops exactly at the top of the ring wear.
If it is a broken ring, and I'm 95% sure it is (or maybe was; you don't know for sure that it is not an old war wound that has been there forever), the fact that the scratch gets deeper as it rises is exactly what I would expect.

Take it down buddy, you know that's the right way.