Z300 TXRC Warning horn and limp mode

[marinemods]

Im thinking it was the sludge in the water accumulator/filter on the motor was the culprit. It was triggering the water detect warning (Thanks again rodbolt17).

I see several versions of the Yamaha tach digital gauge does anyone have a part no. or will any of them work?

The motor is an 03 Z300 TXRC

[boscoe99]

Hope that was it.

Got me confused since you originally said the horn was sounding and the motor was in the limp mode. A water detection switch does not put the motor into RPM reduction (aka limp) mode. And RPM reduction generally limits the engine RPM to about 2000. Also, with the water detection caution system the alarm is turned off when the motor is shifted into gear.

[rodbolt17]

on the 03 model,if equipped with water detect,it will trigger in or out of gear.

sometimes just the red/white wire in the fmm harness laying in the bilge would trigger it,

[boscoe99]

on the 03 model,if equipped with water detect,it will trigger in or out of gear.

sometimes just the red/white wire in the fmm harness laying in the bilge would trigger it,

Which water detection switch are we talking about? The engine mounted one or the optional one that can be added to a Racor style filter element?

OP appears to be talking about the engine mounted water separating fuel filter. The red/white wire is part of the optional fuel filter connected to the FMM, if such parts are installed.

Are you saying that information is conveyed from the FMM to the ECU if and when the FMM water detection switch is closed?

[rodbolt17]

you will get a water detect if that red/white wire gets wet in salt water in the bilge, wont get RPM reduction but it will set the visual.
on the Z300 the thermosensor doesn't control the overtemp alarm, only the tempswitchs.
not all the early Zmotors had water detect,was optional and required the FMM.

the motor had it built in but the FMM had the visable,but if the harness was laying in the water the ECU can detect it and then set the alarm.
about 05 and up Yamaha remapped the water detect so it ONLY works,alarms, in N position.
if its in a GEAR position the ECU wont set the alarm nor go into RPM reduction,.
it simply waits until enough water gets in the fuel system and kills itself .

why they engineered it that way only japan knows.