I have a 350 rancher what else can i do besides oil change, new spark plug, clean airfilter, new oil filter, and valve ajustment to keep my bike in tip top shape.

 

Change oil in the front and rear drives once each year.

 

Few other things
-Check all cables and controls for proper adjustment and freedom of movement
-Adjust front and rear brakes
-Set tire pressures
-Lift the quad and check wheel bearings and swing arm pivots for looseness
-Check the charging system
-Check differential breather hoses
-Adjust the fuel air mixture screw on the carb
-Check ball joints, boots and tie rod ends, and their boots
-Check steering column pivot bushing upper and lower bearing
-Look under the housing recoil for oil seeping
-Feel the boot between engine and swing arm (Make sure it is not soft from a rear engine seal leaking)
-Pull the air box drain/trap empty it and clean

----- Gimpster -----