Furuno Reading Accuracy Help Please

[Chimo]

Just installed a new Mod P66 Triducer (525ST - PWC equivalent ) on my Vag for the FCV 667 and the speed readings are low compared to my GPS output. Eg at about 6kn triducer is showing about 4Kn and so on. I guess the distance log may be out too?

Will doing a reset at turn on of the FCV 667 help or are there other ways to fix this .

The previous triducer speed wheel was the same as the GPS until it was lost to the deep.

Cheers
Chimo

[peterbo3]

Hi Chimo,
Those paddle wheels are often very inaccurate especially at slow speeds. Why not remove it & use your GPS because that is what it is designed for.

[Chimo]

Hi Peter

I replaced the old triducer to get the the speed and distance log so I dont want to give up after one trip.
I might just do the rest at startup and see what that does and check at higher speeds too. Any other thoughts?

Cheers
Chimo

[Fed]

It could be tide/current Chimo, the difference between speed over water & speed over ground.

[Chimo]

Fed

Possible but not probable given the location ie slack water where tested.

C
C

[stue2]

Hi Chimo. I think the little wheel is the problem and not the fcv 667. Cant see how a reset will "reset" the wheel calibration. I have seen these that are not as free as ohers.

cheers
Stu

[Smithy]

There are calibrations in the menus to adjust the speed and temp to known temps and speeds. Just tinker with them so they match your GPS if it is slack water or doing two way tests up and down current and split the difference.

[Chimo]

Hi Smithy

I thank you for the suggestion. I did eventually do the reset and then because all else had failed got the operating instructions and found out about the inner menu speed etc calibrations. So after changing the temp back to C I took a guess and made an adjustment to the speed which I will check against the two GPS s also in the boat. Thanks again

Stu Agree neither the wheel nor the FCV 668 is the problem - operator error in that slow to recognize it was time to read the manual as all else was not working!

Cheers
Chimo

PS interesting comment in the Furuno documentation as they reckon the speed / distance wheels are only good for a couple of years in water lubricated high speed craft, I might have to go slower or give it a run in oil slicks from time to time! The last one was good for five or six times their estimate, must be another benefit of two two strokes smoking etc on initial start ups?

[stue2]

Well I had one for nearly 20 years and never new to calibrate it to the wheel. No doubt some krill oil would keep the wheel spinning and also some fresh mix direct from the exhaust would achieve some amazing results as well.

cheers
Stu