I'll second the adjustable wrench. The nut that holds the petcock on to the tank is larger than anything in the tool kit.
I found a nice one at Lowes this is less than 8" long, with a padded handle. It opens to just over 25mm, or 1". It fits in the tool tray with the tool roll.
click for more info
Cell phone. Good towing insurance if you don't know how to change a tire on the side of the road. (I do not. But I do carry a spare tube in case I run into someone that does!)
Take a spare clutch cable. Also check both ends of the cable that is on the bike(s) for proper lubrication. Also check for fraying, especially at the top. When the lever is pulled, the barrel needs to be able to rotate in the hole. If you have never done it, take it apart (you get to adjust your clutch while you are at it! Not a bad thing.) and clean it out real good. Take the barrel off of the cable nipple and clean everything. Then put it back together with a nice bath of clean grease (any kind, as long as it is automotive). The bottom end should receive the same treatment.
Some folks run their spare cable alongside their working cable. If it ever should break, you can fix it in 5 minutes! But with proper maintenance, it should never break. You should look at it at least once a year, and that will probably catch any problems. Throw in a check before any overnight trips, and you are covered.
It's hard to go if a throttle cable breaks, but they are generally less stressed. But if you have the single cable from the control to the splitter to two cables, that splitter needs maintenance every 5-10 years. It can get nasty in there and hang up. Sue needs to write up a procedure for that from her experience!
