Tdub has over 47,000 miles. Runs fine. Good power. Always has used a bit of oil, especially screaming done the highway at 65-70mph drafting SUVs. Uses a bit more oil since my son borrowed her and rode 3 days without checking the oil--got her back and couldn't see anything in the window. That was 31,000 miles ago.
Now she's leaking a bit more oil from the countershaft sprocket area. She's about due for a chain and sprocket set (26,000+ miles on the parts on the bike) and she'll get both seals at the same time. Also some weeping out of the valve covers, she'll get new rings at the next valve check.
i have a 1991 tw. had it now for 10 years bought it with 6000 miles on it. this summer it rooled over 21000. pulled the head off just to see what the cylinder walls look like in it and you can still see the cross hatch in it from factory. now i ride it pretty hard and put heavy oil in it. i use amzoil 20w50 and change it every 1000mi. i also pull the carb off every winter and do a good healthy service on it. i have 15/43 sprockets on it and she cruises like a dream on the highway. i dont take it over 70 like everybody says just because of vibrations. just keep the carb and valves in check and put good oil in it and she will be alright