Yeah i sent mine in to be fixed and it was the puck. Had I known about the battery and the access to it, I would've done it myself as well. Good gouge for future reference, thanks.

In some earlier threads on this subject, some tried to replace the battery themselves and ruined their pucks, which cost $200+ (so I've been told). I probably could have changed my own, but chose to send it back, just for my own peace of mind! Glad to hear it was only $4

Following up on this thread, thought I would share my experience. No warning, went out to test some new prop work from BBlades today only to find the Speedo pegged at 55 MPH. Pissed off the remainder of the day, I stumbled onto this thread the next morning. the pictures below are from the Monday morning operation. The small Panasonic battery is soldered in and mounting tabs appear to block any additional information. i am going to call Livorsi this morning and see if I can purchase the battery from them unless Stogie can post up the Batteries Plus part number he used.

Pulled the battery mounting clips off and as you can see it is a CR1632

Pretty sweet deal. the guy shrink wraped the sides, bent new tabs and spot welded them on for under $4 bucks

Some have emailed me about the torque required to remove (or in my case install) the white plastic cover. Since mine was siliconed to the top of the dash, I was able to unscrew the cover while still in the boat. However overcoming the pipe tape and o-ring resistance during install was a bit tricking since the unit was no longer secured to the dash. For those that have the antenna already out or when reinstalling, the trick i used was a pair of needle nose pliers. In the base of the unit are three screw holes used to secure the MB from the inside. The remaining thread provides just enough depth to get the tips of the pliers to resist the torque needed to get the cap on or off. Hope this helps.

That's what I did too.

mines running at 9 o'clock ..sure hope it stays stuck to the dash ..Thanks for the great info ...off to Radio shack

i replaced my battery. but the problem persists. mine stays stuck below the 2 ...or at 17 mph..... when i pressthe recall erase toggle, it drops to zero, then when i let go the toggle, it goes back to the 17 mph mark and wont budge ..even when at 50mph, stuck at 17... i keepplaying with the erase and recall togglle but no matter what i do, it always goes back to 17. any ideas

Are you sure you have the +/- soldered in the right orientation?