Pete / Jack - thanks for the info!

Just got my cylinder back from Q&E machine shop in Anaheim, another great tip I got from this site! Going to put in dishwasher tomorrow when wife is at work!

I'm not sure I'd use the dishwasher. Might get it clean but I tried it once with an old cylinder first and it came out with the bore rusted pretty bad.

good point!
i will do it by hand when I am ready for it
thanks!

Did the machine shop not clean the cylinder after bore? I just got a cylinder back from Bill Bune and haven’t looked closely at it but would think it would be cleaned of metal as part of the boring.

Part or their warranty policy reads
"It is the responsibility of the mechanic installing the cylinder, to check the bore and the

piston-to-wall clearance, as well as cleaning and oiling the cylinder before installation."

Enduronut spoiled us.

Shops will rinse but the responsibility for final cleaning is always with the installer.

It's important to clean the ports carefully... especially the transfers... as grit and swarf can hide there. I start with brake clean.

For the bore itself I like to use oil and paper towels. ATF seems to clean the best. I've used motor oil or WD40 too. I just keep oiling down the bore and wiping it clean until the paper towels stop getting dirty. Tedious process sometimes but worth the effort.

There are other methods... but that's what I settled on as best...

Bore job very nice
Vance at Q&E was awesome and to Mark’s point cautioned me to throughly clean and oil prior to assembly.

This doesn’t seem too unreasonable

okay - so i cleaned and cleaned and cleaned and then oiled it up nice and put rings in to measure gap per manual

both end gaps measured .020", which is on the top of the .012" - .020" in the Yamaha manual, which makes me uncomfortable

I mic-ed the piston skirt (1st OS) and it comes in at 3.158, which is 80.21mm, precisely 0.25mm larger than the STD piston of 79.96mm. Moreover, the bore is really nice and tight, honed to 0.002" clearance max.

I did some quick math:

STD bore = STD piston (79.96mm) 3.148" + .002 clearance = 3.150"

1st OS bore = 1st OS piston (80.21mm) 3.158" + .002 clearance = 3.160"

pi x (3.160 - 3.150) = 0.031 of circumference....my point is that it doesn't take much on the OD to eat up end gap so is it possible that the 1s OS rings I bought were STD ones put into the package below? I did get snookered on the first set of seals and that got me a meltdown so I am going to take a break for now.

Advice please, thank you

Martin