piston rings

[Martin]

Im rebuilding my sons GSF400, having de gummed the piston rings I cant find any markings for top and bottom of the rings. The manual says they are marked and that the second ring has a taper on it. Ive looked a t all 8 and cant find any markings. Anyone got any ideas?

[lowrider]

Has it been rebuilt before.
Wrong rings used then

[Martin]

I dont know if its been rebuit before, its only done a genuine 28K miles so I dont think so. If they a not asymetrical does it matter which way up?

[John Hopkins]

As it's too late to suggest laying them down in the order you take them out...the taper be should be on the inside of the ring or it may be on the ends of the ring (at the gap) but if the manual says there is one, there usually is...measure each one with a vernier or micrometer to see if one is different...last resort buy new ones...John

[kiffer38]

a tapered piston ring is normally an oil scraper ring, it goes below the top piston ring, but above the oil control rings, which there are normally about 3 of in the same groove in the piston, i think the taper faces up, but dont quote me on that, as im stupid, and cant remember :D

[Martin]

My dad is a toolmaker, we had a look at these on a shodowgraph and cannot detect the taper. I did keep these in the order that they came off The first ring (top) is radiused equally on both edges whereas the 2nd ring definately had square edges. Information I have seen on the net suggests that the taper is to assist "bedding in " when new and that they flatten off with use. As this is the oil Scraper ring I think I will have to take a chance.

[John Hopkins]

Hey don't get too serious about it... I've seen a bike run with a wooden piston and another with an austin seven piston cut to size on a lathe...If you kept them in the same order and cleaned everything it will be fine...turn it over by hand a few times to make sure it moves freely before you run it, and it's gotta be a lot better than it was....don't forget to run it in as if it was a new bike...John