Question regarding prop slip

[tmanis0182]

Took the boat out with my son on Quaddick lake in Thompson and got to really open it up, figure out the motor tilt for best performance and had my Garmin 60CX with me on the console to record my top speed. Based on what I calculated I am experiencing about 13% prop slip, but I was hoping someone could verify that for me, and let me know if this is an acceptable amount of slip. Here are the numbers. Boat is a 17 ft v-hull Bass Tracker 1300 lbs, generally two adults on board with a 6 gallon gas tank and one battery, 1998 Mercury 40hp 3 cyl. 2 stroke with a Turning Point 12p prop, tach showed 5200 rpms at WOT and my GPS recorded 27.9 mph as my fastest speed.

Thanks in advance!

 

[hwsiii]

Re: Question regarding prop slip

T, I recommend changing props at 15% prop slip and you are close.

You might try reading this for a better understanding of changing props for better performance, and for the major differences between aluminum props and stainless steel.

http://forums.iboats.com/showthread.php?t=369057

I need to know how high your anti ventilation plate is above the bottom of the boat, will you take about 3 pictures for me, using the method I show you in the white paper above. If we can move the motor up some we can reduce your prop slip and gain you some speed.



H

 

[tmanis0182]

Re: Question regarding prop slip

hwsiii,
I will try to get out there Tuesday and snap some photos (it's raining like heck here today). And thanks for the schooling on prop slip, good reading. I do recall taking a look at how the anti-cavitation plate lined up with the bottom line of the hull when I first bolted on the motor, and it was just about in line if not maybe a half inch higher than the hull, but I will get some pictures.