speedometer not working

[mrjigger]

I have a 175 vmax hpdi on a crestliner 182 tourney series. The speedometer on my boat will not read the speed. The arm on the speedometer does not move at all. Any idea how the speedometer works? I have seen boats with the spinner on the back of the boat which reads the speed the boat is moving, but my boat does not have that. Is it something internally in the motor? thanks

[Ralph Wiggum]

Usually, there is a tube and water pressure is used to gauge the speed. I think on Yamaha's the speedo tube might be on your lower unit. Some motors have a separate tube, though. See if you can find it and see if it is blocked.

[marine_man]

The speedometer works based on water pressure. The faster you go the higher the pressure, and the higher the speed.

Also, the paddle wheel speedometers are more accurate at low speed.. and that's about the extent of it (like trolling speed).

In regard to your boat, your motor has a built in speedometer pickup in the leading edge of the gear case. If you look really close at the leading edge you'll see a tiny notch w/a hole in it. That's the water pickup for your speedometer. If you look for a rubber tube running out from the lower unit right where it connects to the motor mid section you should see a splice where the boat speedo tube connects to the lower unit pickup. Disconnect one hose from the splice. Take a air compressor, and with lower pressure, blow some air into the tube until you see it read on the speedometer gauge. If that works it's not the gauge.

Then I'd take the air compressor nozzle and blow it on the other hose, forcing whatever is stuck in there out.

Good luck!

marine_man

[mnfishman]

Take a small drill bit and by hand screw it in the pickup hole that is in the front edge of the lower unit. It is a small hole about 1/8 of an inch about 3" up from the bottom of the bullet on your lower unit. They can get crammed full of weeds and this causes the speedo to stop working.

Make sure you don't use a power drill or even a hand drill use your fingers to turn the bit to pull the obstruction out.

[anchor man]

I have a Yam F150 and ran over a small chunk of wood recently. Wood particles plugged up the small hole and I have zero speedo reading right now as well. Wasn't accurate anyway so I haven't gotten around to clearing the hole.