How to zero a speedometer?

[Rookie Boatman]

I've checked dozens of other speedometer posts, and can't seem to find any information on this. My speedometer seems to work (goes from 16 to around 40 mph, with a 40hp motor on a 15.5' aluminum boat), but doesn't go to zero. Is there an easy way to reset it? It's not a huge deal -- I can do the math by making 16 my "zero" -- but it would be nice to see it working right (ie. from 0 to 25 mph or so).

Thanks!

 

[QC]

Re: How to zero a speedometer?

Have you verified that it is right at the top speed? GPS? They don't really work well below 20 MPH anyway . . . Driven by water pressure. Some are very inaccurate and most here would say your lucky the thing even moves. You could try and check the tube up to it from the pitot, blow in it and see what happens . . .

Have you tapped on the glass? Seriously. Also could try the BFH approach . .

 

[45Auto]

Re: How to zero a speedometer?

My Faria speedometer had a small screw on the back you could turn to zero the speedo. It would only go down to 20 MPH instead of zero when I got the boat, and seemed to stay about 20 MPH high. Made you think the boat was fast though!! Reset it to zero and it worked great after that. It was real close to GPS readings (above 20 MPH, as QC said).

 

[QC]

Re: How to zero a speedometer?

Despite all of the comments around here, my last two Faria's with a Merc Bravo and an Alpha (drive integrated pitot) were VERY accurate above 20 MPH. Within 2% at all speeds up there.

 

[Rookie Boatman]

Re: How to zero a speedometer?

Thanks for the help, but it seems like it's stuck for good. There's no screw to adjust the indicator, and giving it a tap/whack or two doesn't change anything either. Not a big deal, though. Thanks for the help, anyway!

 

[The Great Escape II]

Re: How to zero a speedometer?

Who is the manufacturer? If it's Faria they have a lifetime warranty. You can send it to the for repair. Not all speedo's are adjustable.