Hi all, got myself a 1992 FZR400RR, have noticed some blue smoke from the exhaust on start up and occaisionally while riding? when i open up the throttle the smoke clears, when i shut the throttle off & open up again some blue smoke appears?? have been told it's more than likely valve stem oil seals, has anyone experienced this before? if so how easy was it to repair? with the lack of a workshop manual to work from i'd be kinda working blind!!

Any help or advice would be great, thanks

That does sound like the valve stem oil seals have gone.

I haven't replaced them before but i am going to be overhauling my 3TJ engine shortly and i will be stripping the head so if you still need advice in a couple of weeks time i might be able to help.

ok thanks, give me a shout when you've done the overhaul.

Get it compression tested.
You can do a "dry" test and if it's low or leaks down you follow it with a "wet" test. This is some oil down the barrels, if this holds it's compression it's the rings (as the oil seals the cylinder better) if it still loses its the valves not sealing.
Alothough you can do the oil seals with the head on the engine it will be easier if it's off. Consider honing the bores too.

Evilchicken0 wrote:Get it compression tested.
You can do a "dry" test and if it's low or leaks down you follow it with a "wet" test. This is some oil down the barrels, if this holds it's compression it's the rings (as the oil seals the cylinder better) if it still loses its the valves not sealing.
Alothough you can do the oil seals with the head on the engine it will be easier if it's off. Consider honing the bores too.

valve stem seals, not rings so dont worry yourself that it needs serious work.

valve stem seals, not rings so dont worry yourself that it needs serious work

Don't you need to take the cams of and the collets that stop the valves dropping and the valve springs ... so don't you need to take head off in case you drop the valve and so you can get the spring compressor on .... ????
So given that you might as well compression test it and if there's any leak down now is the time to sort it out.

You can get a gadget that blows air down the plug hole that keeps the valves in place while you work on the stem seals. :)