OK, thanks for narrowing it down for me, and helping identify an RC valve issue. The bike's just recently acquired, with a long storage just before I got her - which would point to a gummed up carb except that the PO said he had the carb cleaned out just before I bought it. But we're talking bike mechanics in Bangkok... so I may have to pull & clean it meself. I'm going to go through the whole bike bit by bit to get it sorted so it'll be good for some trips.

-bdb