I have a 2006 40 hp Merc 4 stroke that runs gr8 but 25's 30's are keeping up. what's the problem?

Question

2006 Mercury 40hp 4 stroke EFI Outboard, long shaft, tiller handle, alternator. Older 40's blowing by me and I can't have that happen to me

Answer 1

There are many variables that influence  boat speed.  Lower HP motors can push a boat faster than higher HP motors if they are pushing a smaller lighter boat. If the other motors are going faster on the exact same type of boat and pushing the same load  (weight)  you may need to change props.

Answer 2

For more speed change your prop to a higher pitch prop. The prop numbers are read by the first number being the diameter of the prop. The second number is how far the prop travels in one revolution. IE: a 14X21 prop moves 21 inches in one revolution.

Answer 3

its probobly the pitch of your prop

Answer 4

carb mortos are faster.... four stoke engines are alittle slower... we get the same ? everyday here in the shop... that guy passed me on the lake.... boat weight, all your gear etc.. has alot to do with it.... prop changes not much in a 40hp

if you were running a 150 and higher then ya there are a hole bunch of different props to try..... just go fish and dont worry about the other guy....