2001 twin 250 ox66 salt water series speed and fuel guage problem

[swabon]

My speed is reading 39 mph as well as the miles increasing even though the boat is not moving, also gas guage is intermitently giving false readings of empty.
Any suggestions on fixing the problem ?
Thanks
Al

[Hamfisted]

The pitot tube on the leading edge of the lower unit could be stopped up with debris, retaining pressure on the speedometer tube. Try disconnecting the tube, either from behind the gauge or at the motor end and see if the speed reading drops off. Then look to clean out the pitot tube of whatever the blockage is.
The intermittent fuel gauge reading is probably corrosion on the wiring at the sender on the tank or the sender itself going bad.


Mike....... Miami, FL

[swabon]

Thanks for your reply.
I have acouple of questions
How do I locate the air tube at the motor?
I couldn't find the info in the owners manual.
Is it a coincidence that the fuel guage and speed malfunctioned at the same time?
I just checked the guages and they are working poperly.
Strange.
Could it be a bad guage?

[Hamfisted]

It's actually a water tube, not an air tube. It reads water pressure at the leading edge of the lower unit, usually the starboard motor in a twin setup. Sure it could be a bad gauge. Check the ground wire (black) at the back of the gauge too. Maybe you'll get lucky.