Adjustable Valve oiling screw G80

[Brushwarrior]

How do i know when this screw needs adjusting?
Is it there because of no valve stem oil seals?

Regards
Steve

[clive]

it adjusts the supply of oil to the valve. The hole in the valve stem often gets blocked with crud anyway. Once set it should not require adjusting. The recommended setting is to screw fully home and then back off no more than 1/6 of a turn, less if your bike is very smokey. If you start hearing a squeak from a valve you have gone too far. I have ridden back from a Jampot Rally with a piece of wood screwed into the hole, just to stop it dribbling down the head with no noticeable difference!

[Rob Harknett]

I do not think valves need much oiling. Mid / late 30's just had a little U pipe coming from the bottom of the rocker box, which some of the oil will drain in. These pipes often fractured and leaked. I had an old 1937 Tiger 80 in the 50's. no pipe on it just a bit of wood plugging up the hole in the rocker box.