Originally Posted by Grinnin
You mentioned oil change. I'd also
- Put stabilizer in the gas tank and petcock
- Drain the carbs
- Remove spark plug and spray in some light oil
- If the bikes have a clock or other always-on drain, disconnect the batteries
- Charge up the batteries once a month
- Put steel wool in muffler exits and airbox intakes to keep out nesting critters.
Modern tires don't flat-spot like tires in the past, so hanging in the air probably isn't required. And I, personally, wouldn't just start them to let them idle, but wait until I wanted a ride and work on them then.
This is just a partial list, I'm sure there will be more.
Great list. Consider replacing the GF, it's sure to be an ongoing issue left unattended.
Too much is just barely enough.....
2007 Tiger 1050
2005 Royal Star Tour DeLuxe
1973 Yamaha TX750 1984 Yamaha RZ350
1974 Norton 850 Commando Roadster