Notchy shifting

Has become the norm--both up and down. Clutch seems to have pressure. Could it be the little orfice screw which is located behind the front chainguard getting plugged? I got it loose but could not extract it--covered with oils (a sign of cloging?).

Any help is appreciated.j

I've read somewhere that poking the hole of the nozzle with a thin guitar string is just as efficient as getting the nozzle out and cleaning it.

Tell me more about this "screw", and what it does.

The clutch oil jet regulates the quantity of oil that gets to the clutch plates.

I got the jet nozzle loose--but couldn't get it out--it was emersed in oil and too slippery. Can you leave it in full tight and just poke through with the wire? I thought I read that oil above the nozzle means it may be clogged.

Would the clogged nozzle cause the shifting to get notchy? Will it damage anything (clutch plates) until I clear the nozzle--assuming it is clogged.

Thanks.

Does anyone know if this jet also affects the oil pressure that goes to the cam chain tennsioner?
I went out for a very fast blast yesterday afternoon to the H cafee between reading and oxford and after parking up for a while when i started the bike up, rear cam chain tennsioner must have had no pressure as it started slapping for a couple of seconds (this is the first time it has happened to me with 6500 miles on the clock and very fast road ridding) but i also still get a very harsh clutch still on low revs below 2500 rpm it sounds like it sticks and not slipping progressly.