I have one vent plug left, Hole shot got better with each of the two that I have removed so far, Engine now “spins” to about 3600 RPMs when prop slips , while boat is getting on plane. I have Pantera III with 2.5 200 Merc. I am still turning better than 6000 on top end. 67 mph @ 5900 RPM 24 Tempest Plus PropShowdawg