Hello all, new member here. I recently bought a 1985 Ranger 340V with a Yamaha 150 of the same year. I took the boat to a marine mechanic before taking it out. The boat is well kept and the motor runs great. Compression was superb on all cylinders. Installed all new lower unit seals, new water pump, ne wplugs, primer bulb and fuel lines. My first time out I noticed the boat labored to get on plane so I suspected the prop as the issue. The prop is stainless but has no stampings whatsoever so i am unable to know the pitch. After doing some research I bought an Amita 4, 14 x 21p 4-blade prop. That only slightly improved the issue so I'm looking for advice. I have the motor trimmed down all the way and I give it full throttle taking off. The bow raises high and after probably a hundred feet or so (guessing) it finally attains plane and does fine. I had it out again yesterday and we had 15-20mph winds. I noticed that starting off into the wind the boat would often not achieve plane at all but just plowed along with the bow high. I realize this boat is on the small side at 16 1/2' but as for weight distribution, the rear livewellls and storage compartments are empty. I've watched the tach while trying to attain plane and it's 3000-3500. I don't care about speed as I'm a recreational fisherman perfectly happy to get to where I'm going at 30mph. Given the size and weight of this boat, I would expect 150hp to pop the boat up on plane rather quickly with a 21 pitch prop. Any advice/opinions?