I have a 2016 ZX 250. The 250 SHO had 218 Hrs and the power head had to be replaced. I got it back last week and as I go through the break in period, currently at 4.5 Hrs, I have noticed the hole shot is terrible now. Before the hole was as good as you could have. Nothing else changed except the new power head. I plan to call the shop today but was curious if anyone had ideas.