2007-2009 Honda TRX300EX TRX300X service manual, Page 55Get this manual
MAINTENANCE SPROCKET INSPECTION Inspect the drive and driven sprocket teeth for wear or damageReplace if necessaryNever use new drive chain on worn sprocketsBoth chain and sprockets must be in good condi tion, or the new replacement parts will wear rapidlyCheck the attaching bolts and nuts on the drive and driven sprocketsIf any are loose, torque them
REPLACEMENT
This vehicle uses drive chain with staked master linkLoosen the drive chain (page 3-14)When using the special tool, follow the manufacturer 's instruction