| Author |
Message |
    
noah sohn
Member
Username: jknoah
Post Number: 17
Registered: 01-2009
| | Posted on Wednesday, July 15, 2009 - 11:21 pm: | 
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I just relocated a pitot tube position to provide a aux. motor then the speed meter doesn't work at all.The pitot tube was close to the motor, now it moved to the boat coner. My question is where is the right location and depth of the pitot tube? The speed meter is old mercury air tube style gauge. thanks |
Graham Lamb
Senior Member
Username: galamb
Post Number: 5664
Registered: 05-2007
| | Posted on Thursday, July 16, 2009 - 12:06 pm: |
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The pitot tube can be located just about anywhere where it will stay submerged during normal operation.
As long as the end thingy that collects the water (not exactly the technical term)  is in fact in the water when you are running it will still create the pressure needed to feed your gauge.
Any chance you pinched or punctured the little air line when you moved it - that would cause a malfunction for sure... |
Benjamin Jones
Advanced Member
Username: benjamin_jones
Post Number: 282
Registered: 04-2008
| | Posted on Friday, July 17, 2009 - 06:33 am: |
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That would be the pick-up? 
As Graham said, make sure the line is not raptured, you could get unwanted water in the tub.
Does the new motor not have a pick-up in the lower gear case? Some do have, look in the leading edge of the gearcase, in line with the prop's shaft. Usually a small, +- 3mm hole. If there, a fitting just above would be the connector point for your pitot line.
I've seen that these pitot type guages are not 70% accurate, checked it against a GPS and was out by miles. Nice to have on the boat, but not always true reflection of performance, especially when comparing prop setup and such.
My  worth...
Happy boating! |
jamie campbell
Advanced Member
Username: outboard_doctor
Post Number: 457
Registered: 02-2009
| | Posted on Friday, July 17, 2009 - 08:23 am: |
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The best spot for it is half way between the engine and chine... if its too far out at speed it will leave the water and the speedo will stop working, |
noah sohn
Member
Username: jknoah
Post Number: 18
Registered: 01-2009
| | Posted on Friday, July 17, 2009 - 09:01 pm: |
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I checked the line, there's no air leaks or damage but I found some water bubbles inside of hose so may be It moved too far out .I'll moved the pitot tube back to the original position tomorrow and test how it works Thanks everybody. |
Benjamin Jones
Advanced Member
Username: benjamin_jones
Post Number: 291
Registered: 04-2008
| | Posted on Saturday, July 25, 2009 - 03:54 am: |
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Air & water bubbles should not pose an issue, it all will compress when pressure comes in from the Pitot pick-up. No cause for concern there.
Is it working since being moved? |
