Buy Yamaha Outboard Parts


No announcement yet.

Port motor no RPMS or key on beep

  • Filter
  • Time
  • Show
Clear All
new posts

  • Port motor no RPMS or key on beep

    I have twin 2005 F225s. I bought the boat a year ago and decided to do the mid section exhaust rebuild. The starboard motors power head was just rebuilt prior to purchase, supposedly ran aground and sucked sand in the motor. Both engines were scoped at that time and looked decent according to marina.

    I got some time a couple weeks ago to rebuild the midsection on the port motor. This process went very smooth, however once the lower unit and power head were all remounted and buttoned up I found out I lost my key on beep for the port motor and had 0 RPMs. Initially I figured I missed a connection, but have looked it over several times and am certain I haven’t.

    Steps taken so far.
    1. confirmed continuity from green wire at ECM connector to the tachometer.
    2. swapped the port and starboard tachometer to confirm gauge was working. The gauge was fine when connected to starboard motor.
    3. Connected YDS to confirm it read the RPMs, it did. I assume the ECM is fine because of this? I did notice a code 28 (irregular shift position) in the YDS, which also made my alarm go off after about 5 minutes of running. All other signals were normal. When I cleared that alarm and moved throttle back and forth it didn’t immediately return and neither did the alarm.
    4. Measured Hz on the green wire, it ranged from 100 to around 600 Hz.
    5. measured Hz for comparison on my starboard motor it measured 70-300 Hz corresponding to 6-30 RPMs. Seems a multiple of 10. This didn’t match what I saw on my port engine.
    6. Based on findings in YDS I also checked the neutral switch and the shift cut switch Both operated as expected.

    I’m scratching my head as what to do next. It just seems odd this would happen when I removed the power head. Did I short something possibly? Any help or suggestions would be greatly appreciated. The good news is my exhaust that I replaced was in very good shape. Zero corrosion at the top of the exhaust, the gasket between mid and power head or the power head. I probably should have not changed it but I already had the components and it was worth the piece of mind.

  • #2
    Anyone with suggestions?

    today I ohmed out the ground (12v -) between the port and starboard male 10 pin connectors and frame. I also ohmed out the 12 v+ at the male connectors also. All was as expected.

    interesting thing is the 12 v - female side of connector on working starboard motor ohms out to the tach. But the port does not, even though at the tach both bullet connectors are jumpered together. My green tach signal on the port motor female side of connector does ohm our correctly to the port tach.

    The black wire is fishy since there is no continuity between the female side of 10 pin connector and port tach black wire. All common is at the same reference and the port tach does ohm our with the starboard common (black wire) in the female 10 pin connector.


    • #3
      well I would think that if you are not getting continuity from on end of the black to the other, that means there is a break in that wire some where in that harness