Free Guide How To Tuning Engine in 4 Easy Steps

If the bike pulls harder at high rpm when cold and less hard when fully warmed up, the main jet is too large. Install a smaller main jet and retest until you find the main jet that pulls the hardest at high rpm when fully warmed up. This must be done first – before moving on to the other tuning ranges. 2. Midrange (full throttle /5k-7k).

Select best needle clip position. To get the best power at full throttle / 5k-7k rpm, adjust the needle height, after you have already selected the best main jet. If the engine pulls better or is smoother at full throttle/5k-7k in a full throttle roll-on starting at <3k when cool but soft and/or rough when at full operating temperature, it is too rich in the midrange and the needle should be lowered.