just did a bit of a search & [think] you must mean the 'ultralite' type which i can't find much info on--But--looking at the pics all the others 'except that' look like a valve type so they probably have the old yamaha type where a needle is inserted through rubber piece. The yam valve really was just a solid bit of rubber [like cut off a heavy o-ring] & oiled then forced into the hole about 10mm deep. Valve assembly outer thread that screws into the body was 1/4 gas thread [tapered thread].
Anyway--that's no help 'is it' but just a bit of 'useless' info. Bottom line 'is' if it's that type then re-gassing is done through a needle hooked to a gauge & nitrogen cylinder with a pressure adjustment gauge. Needle needs to be oiled plus a drop down the hole to the rubber so the needle doesn't have such a hard job pushing through that rubber that it pushes the rubber out the other end [i learn't the hard way bugger it].
If i'm wrong with this info then i'll go back into the --- Mr don't know 'F' all corner--but willing to learn!!. Cheers & hope someone knows the real answer. I'm still living back in the days of re-gassing early TT250's when we had to drill & tap a hole for the valve supplied by Yam--i'd say because they new they would wear before long [& they did] scored the inside body letting gas up into the oil then [boing boing all the way home] sad thing is the late "70's mono's had cast pistons with o rings on & never seemed to wear out--then 'cheap cheap' started using pressed steel pistons in steel bore & before very long they'd pick up & score the shock body [& mix gas with oil]. Now i know why we had to go to a Yamaha Shock School when the first TT/XT250's came out. Sorry--bit off track again. Thanks.
