Speedo Probs

[PhilF]

Happy New Year and safe Boating to you all.
Back from Spain, had 3 really good boating days. Dead clam, sunny but not much heat in the Sun. Surprise, surprise Battery had stayed charged without any assistance since August. Only one prob, speedo not working.
Please where does it take its info from, couldn't find a paddle wheel.
Volvo 175 4.3Ltr Petrol and SX drive. Any help would be appreciated.
Thanks
PhilF

<hr width=100% size=1>

 

[Gtdog]

It is likely that you have one of three types of log input depending upon boat size etc. Either a paddlewheel a sonar or pressure sensor.
The paddle wheel type you say is not present ( have you looked for a transom mounted one?), so on to the sonar type, they look just like a depth transducer and work in a similar way, normaly found on larger vessels/yachts so hunt for another skin fittling to clean. Finaly you may have a thin plastic tube running down the transom, this is normaly about the dia of a drinking straw, and ends with a plastic fitting designed to protude into the water below the transom and measure the speed of the boat through the water by measuring the pressure of the water being forced into it.

Each of these suffer from marine growth and fowling, so a quick dip may be called for!

Happy hunting,
George

<hr width=100% size=1>Work? You call this Work?

 

[Gtdog]

It is likely that you have one of three types of log input depending upon boat size etc. Either a paddlewheel a sonar or pressure sensor.
The paddle wheel type you say is not present ( have you looked for a transom mounted one?), so on to the sonar type, they look just like a depth transducer and work in a similar way, normal found on larger vessels/yachts so hunt for another skin fittling to clean. Finaly you may have a thin plastic tube running down the transom, this is normaly about the dia of a drinking straw, and ends with a plastic fitting designed to protude into the water below the transom and measure the speed of the boat through the water by measuring the pressure of the water being forced into it.

Happy hunting,
George

<hr width=100% size=1>Work? You call this Work?

 

[PhilF]

Thanks for that, now you mention it I remember seeing an umbilical type thing when the Boat was launched.
The drive was quite badly fouled this time and you are probably spot on.
Have to wait til Feb to find out fortunately
PhilF

<hr width=100% size=1>

 

[BrendanS]

don't legs like mercruiser alpha have a fourth type - little hole in leading edge of leg (similar to type 3, but built in, so no tube on transom)

<hr width=100% size=1> I asked an economist for her phone number....and she gave me an estimate

 

[jhr]

Yup. There's a little V-shaped notch on the leading edge of my Alpha 1, which the handbook tells me is for the speedo. Dunno exactly how it works and/or if there's an impellor hidden in there, but my speedo has gone awol as well, so I'm in the process of trying to find out!

<hr width=100% size=1>

 

[BrendanS]

It'll be like a pitot tube. No impellor, just measures pressure at top of a tube some distance away

Checked it's not blocked, but I'd suggest not blowing anything high pressure up it in case you damage the sensor

<hr width=100% size=1> I asked an economist for her phone number....and she gave me an estimate

 

[jhr]

Thanks, Brendan. I'll try lungpower in the first instance and it's also been suggested that I try blowing from the speedo, rather than the business, end - so will give it a go. The problem is that I may not know if I've achieved anything until she goes back in the water (67 days and counting......).

Worth a try, anyway; I'm going to give it a go this weekend.

<hr width=100% size=1>