Topic: piston rings ¿which one should be at the top?

[mazingerzeca]

Hello all. I'm installing new rings on my CB750 K7. I have a doubt on which ring should be at the top. Both are the same width and would be interchangeable on the piston row. One of them (picture 1) is copper color and light grey on the side which contacts the cylinder sleeve, and the other one (picture 2) is dark grey on both sides. Which is the installing order? Thank you.

[Raul CB750K1]

http://forums.sohc4.net/index.php?topic=33833.0

[Alan F.]

Yup, chrome edge at the top, placed in the top groove.  Be careful to get your ring end gaps right.  The tips that I found most useful for measuring end gaps were to place the ring into the piston bore and give it a little push down inside with one of your pistons (top facing down) then use a feeler gauge to check the end gap, remove file some more...reinsert the ring and check again.

I didn't have a clue how this was done until I found the one and only post that spelled it out like this.

Cheers and good luck, be sure to read the 'rebuild for dummies' threads through if you need encouragement or have questions, most of the info is in those threads.

-Alan

[mazingerzeca]

Thanks for the replies.
None of them seems to be chromed. The copper color one could be, but it is light grey, not chrome finish, as you can see in the picture. Should I think this is the chromed one?

[gane]

M, perhaps this will help, the top ring is the lighter grey one, It has a oxidized coating on it's outer edge which aids seating. also, look closely at the face of rings at end gaps, there are usually either an R, or o/s number stamped there, if so this should face up. on 3 piece oil rings, the scraping rings will not be marked, but have an orientation... to determine, simply hold by outside diametre w/end gap to you and squeeze lightly, end gap will flex one direction or the other 9 times out of 10.. it doesn't matter which way you install them, just as long as both agree. hope this helps, G