18' Crestline, 40hp Johnson 4 stroke, 9 pitch prop, 2 People, 18 gal of gas.
It was only giving me about 10 mph's with two people at the Colorado River in Laughlin, what can I do toget it up to atleast 15-18 mph's?
18' Crestline, 40hp Johnson 4 stroke, 9 pitch prop, 2 People, 18 gal of gas.
It was only giving me about 10 mph's with two people at the Colorado River in Laughlin, what can I do toget it up to atleast 15-18 mph's?
I don't know what the speed of the river was, I know that my tach was reading 5600 rpm's and I wasn't using a gps, I was going of my speedo. The speedo is the type that has a plastic tube and measures pressure I guess.
Your speedometer measures speed over water. Think about affects of river.
If you were going down river and the current was moving at 10 mph, the speed over water, plus the current at 10 mph adds up to 20 mph over ground.
If you were going up river with same current speed, the speed over water, minus the current at 10 mph equals 0 mph over ground. Essentially making no headway with reference to the shoreline.
Test Drive
Test Engine: Mercury 4-stroke, 60-hp
Test Prop: 10" Vengeance
Test Load: People (400 lb.); Fuel (11 gal.)
Top Speed: 21 MPH @ 5,500 RPM
Time to 15 MPH: 5.0 sec.
Just an FYI on measuring speed with boat's speedo Vs GPS.
I have a 60 HP Merc BF ( 2-cycle) on a 24 footer. wide open, I get 5800 on the tach., and the speedo indicated ~ 12MPH, the GPS said 19MPH ( 2 people). So I'm not sure what a 40HP would get, but don't expect much more.
