i have a set of yamaha 200 hpdi they have seperate sender units for the fuel managament but run to one gauge they were both reading properly to the gallon as far as burn distance and all that and now it is only reading one motor any ideas to what may have caused this the system is only 54 hours old on the meter and is only 9 months old as far as date from purchase thanks for any help you can give
The gauge is apparently ok but has lost its input from the other motor. I'm familiar with "in the fuel line transducers" but I'm not familiar with the Yamaha system. If that system has an in-line fuel flow transducer, it may have gone bad or the turbine wheel has stuck. If the engine ECM drives the gauge then that's a real "gray" area and one that may require a trip to the shop. Like my car, the ECM can very accurately calculate fuel consumption from injector pulse width and known flow rate at that pulse width. You might check the back of the gauge as it may be the signal lead from the engine may be disconnected.