Yamaha 100 champ wont start but it will pull start? it Just cranks with the key but when I get it running it will start every time after that.with the key. Until the next day I have the same problem. Any HELP?

Sounds like a battery that will not hold a charge. When the battery is low all the juice goes to the starter. Not enough left for a good spark. Kick it and the juice is there for the spark. Once running for a short bit the battery gets recharged so the key works all day. Then the battery dissapates the charge overnight.

Befor you spen $50 or so on a battery, look to see if there is water covering the top of the battery plates. If so then the current battery needs to be replaced. If not, add water to cover the top of the plates and ride it for a day. See if it holds a charge now. Battery may still be bad but it was worth a shot.

Please rate this answer. Thanks jnsocia!

Its your battery, but not sure what you mean by cranking it for 10 minutes. check fuel lines, take the carb off and clean that, also check inside gas tank for anything blocking fuel flow. to the useless poster above its 100cc air cooled 4 stroke from the late 90s i have same thing for my son. most of them you can get the fluid at auto parts store, take in your old battery, see if they can help you get the fluid. the pull/kick start suggestions are useless as this machine has only electric start.