I just bought my 85 about a month ago. When i got it the thing was so torquey. I could start out in second gear without and drawbacks. But just recently it lost like half of its power. I can beraly start out in second now and it kinda feels like my fuel filter is bad. When i am driving up a hill it does this weird shakey thing. It will go and hesitate go and hesitate kinda fast but enough to where you go up and down in the seat. What could this be? plugs? fuel filter? maybe even fuel pump?