extra spark plug ,socket to change it with. sockets for tighting bolts, extra fuel line,maybe a few other tools (screwdrivers,etc.) i always have my tools with me when i ride more than a mile
ok heres what i have always attached to my bike and im so glad that i do when i need em
allen wrench multy tool
screw drivers flat and phillips
10, 15 and two 13 mm wrenches and several cresent wrenches
extra tubes
air pump
brake pads
fuel line
duct tape
string
and a knife
now thats all dandy for bike tools but if your lke me you also include a survival kit when you leave the house consisting of
rain gear
extra socks
water proof socks
hat gloves
sweater
fire starting stuff including magnesium striker cotton and vasoline several types of lighters butane zippo and bics matches and usually aanother pair of gloves for gathering kidling and wood
i carry alot with me most guys dont really have to worry about it but its cold here and starting a fire and staying dry is very imprtant to survival
anyway i have more miscellaneous stuff but that is the gest of it different seasons have different tools and such