This will fix your half-tank lean issues; if you still run hot, you're gonna have to do some work.... Remove the engine. Take off the roto-backplate/pullstart. Remove the back cover and use a hi-temp gasket sealer from the autoparts store. Now remove the carb and seal the neck. Those NS25s sometimes seem to like leaking air....
http://www.neweramodels.com/cgi-bin/...i?part_id=1704
