Re: Lund 1660 Speed/Planing w/25hp?
Don't know if you made a decision yet as this is an old post. I'll post this anyway so maybe I can prevent another member from making the same mistake. My first motor 2 months ago was a 2005 (new in box) Mercury 30 4 stroke EFI that the dealer mounted on my 2007 1425 Lund Classic SS turned out to be an incredible dog.
Took at least 100-200 yards to plane with only my Wife and I aboard. A 10 mph headwind and fagadaboutit planing at all unless I moved out from behind the wheel and practically had to hang off the bow to get it to plane. And then another boat cuts across your path and you slow down for his wake and you get to do it all over again. 3rd person on board, no way!
Dealer said he later discovered a throttle problem when he sold it to someone else, but I never bought that explanation.
The other poster was right on the money . . . try it out on the water first. You will NEVER be happy with a 25 hp on a 16 foot boat. I can guarantee that!
I finally had them swap the 30 for a 40 Merc and I'm happy as a clam now

Boat pops up on plane in about 10 feet. Top end about 32 mph with 2 or 3 on board. Never had 4 people yet to test the top end and planing out.
If in doubt, ALWAYS go with the Max hp the boat is rated for. I always knew that, but tried to save a few dollars anyway and was very unhappy with the first motor's performance.