Hi. Got a 1985 Yamaha QT50 that is slow off the line. From 0 to about 15 MPH. Then after 15 MPH it shows good power to about topping off around 27 MPH.
Question 1: What could be some reasons why it is slow off the line, but good after hitting about 15 MPH?
Question 2: Any simple things to make it actually do 30 MPH or more?
Question 3: The NGK BP4HS spark plug is impossible to find. Any recommendations on a more popular brand and model?
Question 4: Would a new ignition coil help?