i am on my second gambler ,, this one is a 1995 21 foot with a 1996 mariner 200 super magnum motor.with a tempest 3 blade speed prop.. i am only getting 68 mph on gps but i get a chime walk, and cant get the boat to power through it. i am turnning around 6000 to 6200 rpms.. my old gambler would gps at 72 mph, at 6400 rpms and at aroung 68 to 69 mph it would walk some but i could power through it..any ideas.. thanks tom
Shawn is right, never try to "power through" CHINE walk. Steering correction is the only way to safely do it.
You should be getting better speed but more information is needed. Things needed to know are:
Not only the name of the prop and the number of blades, but also the pitch of the prop.
Do you have a jackplate?
What is the engine setback?
How high is the engine set? What is the distance in inches from the centerline of the prop shaft to the bottom of the pad when the propshaft is perpendicular to the pad?
What is your engine's water pressure when running at wide open throttle?
Give us this information and we can make some more educated guesses as to the problem.
My initial impression is that the motor is either set too low or too high.