pp speed vs gauge speed

[Whitetail15]

my perfect pass speed is 3 mph slower than my boat gauge reads at 20, then the faster you go the more they are different. guess i have to put my gps in the the boat and see witch one is correct. are they both adjustable?

[Chexi]

Need details. What model and year boat do you have. If 2000-2002, do you have the digital gauges or the analog Faria replacements? Is your speedo controlled by a pitot tube or by a paddlewheel? Which version of PP do you have? Is it paddlewheel or gps based?

Generally, both the speedo and PP are correctable for speed being off. Speedos have a potentiometer that you can adjust on the back with a small straight slot screwdriver (or sometimes they have a breakout potentiometer with a knob), and PP has a digital setting that you can adjust. As you noted, bring a Garmin or other portable GPS on your boat to figure out which (if either) is correct, and then you can adjust from there.

[Whitetail15]

sorry for lack of info: here it is.

2005 196 limited. zr6 motor. boat speedo is pilot tubes, and pp 6.5 is paddlewheel.

here is another thing. i looked under the boat to check the paddlewheel and it is not perfectly parallel with the keel. it is almost perfect but if i could turn it a little i would. i took it apart from the inside thinking i could turn it a little and install it back it but there is a notch that keeps it aligned with the housing. i believe the entire housing would have to be turned a little to move it. i am sure it is sealed pretty good and would not be worth the trouble unless someone thinks that is part of my problem.

i am going to try to get a gps number this week to start with.

[Chexi]

Ok, so we know now that your speedo is a pitot tube and your PP is paddlewheel, so separate input mechanisms. This helps. I would check witha portable gps and adjust from there. I would not mess with the paddlewheel orientation, at least not yet. Actually, if it is a problem, I'd just bypass it with a nauticlaugic setup (pending my review on that product which I hope to get out next weekend).

[AirTool]

Wow. I didn't realize pitots were included all the way to 2005. My 2006 (TBW) has both units read from the paddlewheel.