Its probably worth working through the following things (had a bit time to think on it):
- Do the air filter
- Seal the tank with POR15 kit or similar
http://www.frost.co.uk/por15-motorcy...epair-kit.html
- Rebuild the Fuel tap and change the hoses (if you haven't already done it), adding an external fuel filter in
- Get the carb bowls open and give them a clean out (budget for a full rebuild)
- Carb balance
I'm going off what issues I had a few years ago with fuelling
Also shouldn't have yet lanky use it
