Piston rings ?

[JonD]

I have just bought some Nippon NPR rings for a Z900, the top compression ring has no marking on it to show which way up to install.Has anybody fitted these rings and will it matter as all other rings that I have used on other bikes normaly is marked in some way ( the second ring has an N etched on the top face). Any advice will be apriciated as the bike smokes like a wood burner at the moment on start up but mostly clears to a mild dark cloud after a couple of miles.[/b]

[debben1]

Hello JonD, Smoking on start up could also be a sign of worn valve guides and hardened valve stem seals, black sooty smoke can be a sympton of a rich mixture, while the cylinder head is off it would be worth checking the guides. Regards, Steve

[JonD]

Thanks Debbans I have fitted valve seals 500miles ago (yours), the guides and valves are within tolerance so I have bought rings even though the ones on the bike looks ok. once agan the symtems are as follow
start up cold clear for ten seconds
increasing gray smoke untill I am stood in a cloud of white/gray smoke
ride off to the laughter of my next door neighbour
after a mile or so I am down to a wisp of dark gray smoke which increases on acceleration!!!!! any ideas would be concidered
thanks Jon

[JonD]

Thanks Debbans I have fitted valve seals 500miles ago (yours), the guides and valves are within tolerance so I have bought rings even though the ones on the bike looks ok. once agan the symtems are as follow
start up cold clear for ten seconds
increasing gray smoke untill I am stood in a cloud of white/gray smoke
ride off to the laughter of my next door neighbour
after a mile or so I am down to a wisp of dark gray smoke which increases on acceleration!!!!! any ideas would be concidered
thanks Jon

[Garn 1]

JonD, my opinion on the unmarked top rings would be to use them any way round. However, be careful as sometimes they are ridiculously hard to see. Use a magnifying glass and really study both sides for that small "N", usually near the gap. If you have inspected them thoroughly and find no signs of a stamping or change in the symmetrical shape of these top rings, then it must be assumed they can go either way.
RegardZ

[debben1]

JonD, Overfilling the oil level can cause smoking, only fill to between the levels and not to the top level, certain oils also can give this problem, what oil are you using, replacing the rings will at least eliminate the questoin mark over worn rings, Regards, Steve.

[JonD]

thanks folks for the help, i will put the new rings in and change the oil (not halfords own this time )

[Pigford]

JonD.....

When you change the rings ... DO PUT HALFORDS CHEAPO OIL IN..... or sumink plain - DEFO not synthetic

This will help the rings BED-IN

Then after a few hungred miles, change filter & oil for the better stuff

[ROZZER]

I agree with Garn, I had my Z1 rebored, fitted one top ring upside down (cos markings are really hard to see) bike smoked like a Philip Morris Beagle. Suggest a hone/glaze bust before fitting new rings too.