i own a 1975 skiddoo tnt. it has a 440 engine but has trouble running. I prime it three times to start and usually first pull starts it. I go ridding for about 10 min. and the thing starts to bog down on me to the point where it stalls completely. i can prime while it is about to die and manage to keep it running a little longer until it dies. I need help i have no clue i am pretty sure it is lack of fuel but don't know if it is carb or fuel pump. thanks for your help.