Time for an update, and not a good one sadly... Today I thought I would get the engine buttoned back up after a long period of sitting while my friend from Germany was visiting. Instead, after the first pass over the head with the torque wrench, I discovered part of an oil ring on the garage floor that I assumed was ejected while I was seating the cylinders a few weeks ago. Several words exited my mouth at this point 
And sure enough after removing the head nuts, head, and cylinders again, I found the #4 piston with ⅔ of an oil ring and a some nice gouges along the cylinder wall...
The scratch is 2.5" long from the bottom of the cylinder sleeve, and my tape-measured dimensions tell me the bottom of the oil ring sits ~0.75" below the top of the piston crown. With a 2.0" stroke, that puts the new oil ring 0.25" into the scratched portion of the cylinder sleeve. It's deep enough that I can feel it with my finger, but I'm trying to decide if I can salvage the sleeve somehow either with another partial hone only over the scratch or - if it isn't that deep - if I can just get away with it.
Are these rings decent enough? Don't want to break the bank on this thing. http://www.ebay.com/itm/72-74-Honda-CB350Four-Standard-Piston-Rings-Set-4-rings-Include-11-CB350FPR-/162019454483?hash=item25b91cae13:g:ARoAAOSwk5FUtjrs&vxp=mtr
Hopefully the next update will be a happier one!
Aha...welcome to the scratched cylinder and snapped ring club! At lest we are both in this one together...as grcamna2 mentioned, I'd happily go 50/50 on a cylinder
block with you. I need two sleeves, sounds like you need one.
As for rings, I was weary of anything other than OEM. It took me a while and cost a pretty penny but I found them from a dealer in Canada. $170.38 for a set of four. Unopened in the OEM box, they really are a thing of beauty! Shame I'll have to open them...but they'll serve my bike well. Many recommendations on my thread were to overbore a size up. Why scratches are not too deep so one size up (0.25") should do. Seeing as how I spent all that money on the rings, this was not exactly something I wanted to do...that being said, it could be a decent option for one of us. If you'd like to stick with the STD bore I'd be happy to sell you my rings for what I paid for them.
The third option is an aftermarket sleeve. I reached out to two companies, one LA Sleeve, the other Bill Moeller at Bore Tech. LA Sleeve got back to me and said it would be $150 per sleeve and that they had one in stock. Six weeks lead time to make another. Yikes! But alas, in desperation, a good option to have.
We're in the same boat here sadly, and not with any real obvious "good" answer. I'm pretty sure you have my number so feel free to call or text if you want to chat options!
EDIT: Looks like Larry could be a good option!
I have a spare cylinder set along with at least two full sets of std. pistons...Larry
Is your set the sleeves or the head as a whole? Thanks for chiming in!
