Bubbasboat
Chief Petty Officer
- Joined
- Mar 8, 2014
- Messages
- 467
I want to replace my speedometer system, it's pretty cheesy and old as well. I'm not looking for exotic, just an honestly priced, good working and reliable system. Any suggestions?
It sounds like you are replacing it for cosmetic reasons.
Speedometers are all inherently the same.
Expect the new one to work just as well as the old one, only look different.
How big is the budget?
FYI, other than the light, they are not electrical devices.
They are not vacuum.
They work off of the water pressure from the Pitot tube on the transom or built into the lower drive unit.
If you can not develop pressure from the water. You will not get any speed indication.
Blow by mouth, as hard as you can into the pickup hose. Expect to see ~10 mph.
What Speedometer? What Boat? What drive? Details!
In reality, pivot tubes work off air pressure. The water pressure compresses the air inside the tube that generates the force on the gauge. Once water gets inside the tube, performance suffers greatly.Sorry, I did know that. I'll try the blow test. Mine is the pitot tube on transom. Also an old system. Thanks
I want to replace my speedometer system, it's pretty cheesy and old as well. I'm not looking for exotic, just an honestly priced, good working and reliable system. Any suggestions?
I would like to thank everyone for all the absolutely great information about servicing a speedometer system!
I NEED to replace my system, Pitot tube, speedometer, etc. This has not worked since I got the boat. It's no big deal, access is great on my hull and interior!!
Should I spend $10 for all the parts, or should I pay $150? I need it to work reliably,
I don't go that fast anyway, more curiosity how fast I'm really going!! I am putting a 70hp on it, the boat in my profile photo. My current hull. OH, FANCY is of no value, just function!
Any thoughts?
Thanks
I personally would trouble shoot and fix what's wrong. It's nothing but the Pivot tube, some hose and the gauge. Never known a pivot tube to go bad unless physically damaged. The tubing has the highest probably for damage...
+1
You could replace the Speedometer and Pitot tube only to find it still does not work because the hose pinched in the middle. Throwing money at a problem is just throwing money away.
If you feel that $20 is not worth the effort to find the problem.
Do this, take $20 out of your wallet right now.
Now burn that $20 just for fun. If you can't bring your self to do that, go find the problem in the boat first.
The Test...
Remove the hose from the pitot tube and blow into the end of it.
The far end of the hose is blocked by the speedometer so no air will actually flow, only pressure.
If you can get air to flow into the hose, it is cut somewhere
A health set of young lungs should be able to blow ~10 mph.
If you get Zero on the gauge, Remove the hose from the back of the gauge. It just pulls off, no connectors.
Blow into the Hose from the gauge end. You should be able to blow air out the open end by the pitot tube.
If not, the tube is Pinched or plugged with mud or insects.
If air comes out the other end, reattach it to the pitot tube and blow again.
If the tube is now blocked, the pitot tube is plugged up with mud or bugs.
Should have asked this first... Is the Pitot tube Mounted Correctly?
View attachment 228918
Perhaps flushing some water through it or the assistance of a fuzzy pipe cleaner would help.
The tube is open at the pitot end but blocked by the Speedometer, so there is no actual flow needed in the tube, only pressure. If the tube is open at all, it will work. At least until it gets plugged up again.
I am glad you didn't go the "Replace Everything" route because of a dirty pitot.
Here is another "Outside of the Box" Idea.
The next time you take the boat out, pull the tube off the pitot and run around at speed for 5-10 minutes.
The pitot will be flushed out by the "Poor Mans Pressure Washer" action of the water.
You many look like an over sized Ski-Doo from the water fountain.![]()