Ok....ignorant alert!
When I'm cruising at 25-35 mph....all good trimmed down tight.
If I want more speed I need to know tthe magic formula to keep bow up and rpm's right.
Any pointers?
150 hp
18' Fiberglass
Here are some pointers. Trim down all the way to take off. After the boat gets on plane, bump the trim up a little at a time. You will feel the bow begin to rise and the speed will increase without adding throttle. Trim up until the boats begins to porpoise. Then bump it down a couple times until the porpoise stops. Now you are set to go.
The trim changes the attitude of the prop in the water and lifts the hull free so there is less wetted surface that creates drag on the water. Less drag equals more speed and more efficiency. So you will also burn less fuel if you are trimmed for optimum performance.
If you are running WOT and you are trimming the motor up and you begin to notice the boat starts to chine walk, bump the down button a couple times to get it to settle down. Your boat should be capable of low to mid-60's if it is set up properly and has the right prop on it.
Also watch the tach on the dash. Do not exceed 6,000 rpms as this could be too high for your motor. If you exceed 6,000 rpms, you need a higher pitch prop. They are rated in "diameter and inches of pitch." An 18' boat with a 150 probably has a 21" to 23" pitch prop.
A good rule of thrumb is the lower the pro pitch, the better the holeshot but it costs you speed on topend. The higher pitch props are typically slower out of the hole but faster on the topend.
