Yes, that little line is the chain oiler. It was the first modification I made to the bike when I got it. Crimped it shut and soldered it. You can't see it in my picture because I have it turned over and it points backwards. I forget how it was all hooked up and routed, but the centre bolt in the chain guard held the end of it. There was plenty of oil leaking around everything to oil the chain, rear wheel and inside the rear guard, transmission, cradle, and plenty left for a puddle under the bike. I also used to get a lot of oil coming out of that hole in the front of the oil tank, that hole goes up into that 'top hat' thing on top of the oil tank and ends there. Breather for the oil tank. It would drip down on top of the trans and the bike was always a mess behind the motor. So far, nothing is coming out of that hole, but I only have 10 miles on it. Some people have trouble and some don't. If I do, I may operate on the oil tank to try to get that breather so no oil can get into it, or run a separate line from that hole down to drip on the ground instead of the trans. I think 69750S (Bruce in Juarez) does that. I solved the oil leaks with Prematex Blue Racing formula Hylomar for all the gaskets and the flange on the crank cases (thanks to hobot). Expensive but effective, $15/1.2oz., but it will do the whole bike.
My plan for the drive chain is to oil it periodically, and when it stretches, get a new one, they are less than $30 from OB. You can spend well over $100 on one though.
Dave
69S