I have a Wooldridge AK II 18.5 with a 115 Yamaha 4s and it needs more power. Any thoughts/recommendations on this? The hull is rated for 175 but there are no factory 175 jets that I'm aware of. The obvious choice is the Yamaha 150 but will I be happy with the performance? I'd hate to drop all the cash on a upgrade and be less that thrilled. The Mercury 4s 150 seems to have good reviews from what little I can find online. Anyone running one in the jet version?