I thought this may be a good place to look for some answers. Sorry it is not a mustang but it does have a ford engine!
I have a problem with my tachometer in my 1974 ski nautique with a 351.
It will read around 1700 RPM when the boat starts up and idles I think it should read around 800 RPM (at least this is what is sounds like). The tach only increases slightly (up to 2000) when the throttle revved and barely moves at all engine speeds. When the throttle is revved drastically the needle moves backwards and pegs to zero rpm.
I have replaced all power and ground wiring to the gauge and checked it. I have checked the continuity between the tach signal wire (gray) at the gauge and at the coil. The tachometer has been replaced with a brand new Nordskog tach, although my old tach behaved the exact same way, leading me to the conclusion that the tachometer is not the problem.
The signal wire (gray) is attached to the negative side of the coil, and this seems to be correct from all the diagrams and tach installations instructions I have read.
Additionally, the boat has been converted to electronic ignition, and I am not sure what bearing if any the would have on a tach signal.
Any suggestions as to how I could fix it would be greatly appreciated as I am at a loss of what to do. Does anyone have any idea what is causing this inaccurate readout or how to fix it?
I have a problem with my tachometer in my 1974 ski nautique with a 351.
It will read around 1700 RPM when the boat starts up and idles I think it should read around 800 RPM (at least this is what is sounds like). The tach only increases slightly (up to 2000) when the throttle revved and barely moves at all engine speeds. When the throttle is revved drastically the needle moves backwards and pegs to zero rpm.
I have replaced all power and ground wiring to the gauge and checked it. I have checked the continuity between the tach signal wire (gray) at the gauge and at the coil. The tachometer has been replaced with a brand new Nordskog tach, although my old tach behaved the exact same way, leading me to the conclusion that the tachometer is not the problem.
The signal wire (gray) is attached to the negative side of the coil, and this seems to be correct from all the diagrams and tach installations instructions I have read.
Additionally, the boat has been converted to electronic ignition, and I am not sure what bearing if any the would have on a tach signal.
Any suggestions as to how I could fix it would be greatly appreciated as I am at a loss of what to do. Does anyone have any idea what is causing this inaccurate readout or how to fix it?
