Speedometer options?

[slowstratos]

My boat has a pilot pickup type speedometer on it. What other options do I have to replace it?

 

[roscoe]

Re: Speedometer options?

Pick up a cheap handheld gps unit.<br />Most accurate, and easiest to not have to install.<br />Also contains a handy gps function. <br /><br />The Cobra gps 100 is only $79 after the rebate.

 

[daddy_coole]

Re: Speedometer options?

you can get gps for $79 <br />over here i havnt seen any for less than £100 (between $150 $200) i need to move country

 

[swist]

Re: Speedometer options?

Well they still make make paddle-wheel type pickups which may be more accurate than pitots but given the moving parts and the tendency to get fouled, I'm not sure they are any better.<br /><br />I also think there are design problems in most cheap marine pitot pickups. Maybe that's why they are cheap. Airplanes have been using pitot tubes for years and their accuracy/reliability requirments are high. Of course air flow and water flow are not the same....<br /><br />In any case a GPS gives you speed over ground, having speed over water (pitot) is VERY useful in high current areas as the different tells you what the current/winds are doing for your progress....

 

[gewf631]

Re: Speedometer options?

I happen to be lucky, in that my dash speedo is accurate (I understand this is pretty rare).<br /><br />I only found this out after purchasing a handheld GPS, but that's an investment I'm glad I made. I went with something about twice the price of that Cobra, but also got mapping, and a cigarette lighter adapter. Being able to mark a fishing spot, or maybe that shallow spot, has come-in very handy. Also, the backtrack function will be useful once I venture-out on some unknown lakes. Checkin' you speed is only part of the fun!<br /><br />The *only* thing I like about my dashboard speedo, is that it's always there.

 

[sangerwaker]

Re: Speedometer options?

The Airguide pitot speedometers are VERY accurate once you have them calibrated (yes, with a GPS). However, they are still a pitot type and do occasionally clog. Ski boat manufacturers have been using them for years.

 

[Mark42]

Re: Speedometer options?

I have a Teleflex pilot speedo (5-35mph range) that performs well on the bay, but tends to collect grass on Lake Hopatcong. I really don't know how accurate it is, but it consistantly reads the same speeds for a given RPM under similar weather conditions. <br /><br />For me it was a great reference when making changes to the boat like prop and trim.<br /><br />All in all, it performes much better than I anticipated after reading about how unreliable and inaccurate pilot type speedo's are.

 

[Speedwagon]

Re: Speedometer options?

I have a question about these pitots. The one on my boat keeps getting flipped horizontally to the boat when I've been out running around for awhile. So when I start the day, It will read OK. But by the end of the day, the readings have dwindled, because the pitot isn't sticking down anymore. Is this caused by a worn out/old pitot? Or are they supposed to do this, and maybe it's placement is wrong?

 

[Mark42]

Re: Speedometer options?

Its probably worn. A new pilot is fairly cheap and available at discount stores. You could see if a shim behind it will work to put back the resistance lost from years of being flipped.<br /><br />BTW, I am beginning to believe a lot of the talk about pilot speedo's being inaccurate is not due to the accuracy of the unit, but more to lack of maintanence or impropper install. Once a season Teleflex says to disconnect BOTH ends of the speedo tube and blow it clear. Do NOT blow air into the speedo, it was not designed to take compressed air pressure. <br /><br />Another misconseption is that the speedo's work on vacumm. Not so, at least for the Teleflex brand. They work on pressure generated by water being forced up the pilot tube while the boat is running. So there is quite a bit of water up the tube, and that is why teleflex says to blow it clear each season to prevent any buildup of crud or mold, etc. It is also a good idea to have the tube run so that water can drain when the boat is at rest.<br /><br />When running in salt, the pilot tube rarely picks up seaweed. But when it does a quick twist of the steering wheel side to side will usually dislodge it. Running on lakes the speedo rarely works due to all the grass it collects. Maybe this is where the complaints about pilot tube speedos come from.