guys my motor spits and coughs at idel,but runs good throdled up. i noticed a bit of oil running down from the top crank seal. could it be bad alowing air to be sucked into the cc? is there anything i can do to test this or should i look elswere? i have a buddy that has a seal puller so it wont be that bad of a change but i thoutght i would ask before getting into it. thx guys!