RPM GAUGE PROBLEM

[RWS]

Hello all, hope you are having a safe,fun summer. we have a 1987 3607 and my starboard RPM gauge is reading 1000 RPM's high. Turn engine off and it drops back to 1000, when you turn key turn key to middle position it goes to zero but when fully turned and engine starts it reads high. Will disconcerting from the coil and reconnecting reset it? Or is it time to just get new gauges?Thank you for you thoughts and stay safe.

[RGrew176]

You could pull the tach and check if there is a knob on the backside of the tach. If there is there would be settings for 4 cyl, 6 cyl 8 cyl and so on. On my last boat the tach's were off and I pulled both of them. They were set on the O/B (outboard) setting. Moved both of them to the 8 cyl setting and all was well.

[Viper]

Ya check the rotary switch as Rick mentioned to ensure it is set properly. If it hasn't been touched and this just started happening, you likely have internal gauge issues or a problem with the wiring; bad connection, corrosion, etc.

The internal contacts on the selector switch tend to corrode over time and cause erratic readings. As a temporary measure, note the position of the switch, then rotate it back and forth several times. This helps clean the contacts in the switch. Note that some switches have to be pushed in slightly first before they will rotate so don't force it. Return the switch to the original position, then run the engine to see if that helped.

If it works, the fix can last for years or not long at all. Chances are it'll happen again as it's an indication that the components inside the gauge are starting to degrade and you should budget for new replacements.

Keep us posted

[RWS]

Source of the post You could pull the tach and check if there is a knob on the backside of the tach. If there is there would be settings for 4 cyl, 6 cyl 8 cyl and so on. On my last boat the tach's were off and I pulled both of them. They were set on the O/B (outboard) setting. Moved both of them to the 8 cyl setting and all was well.

Thank you.

[RWS]

Source of the post Ya check the rotary switch as Rick mentioned to ensure it is set properly. If it hasn't been touched and this just started happening, you likely have internal gauge issues or a problem with the wiring; bad connection, corrosion, etc.

The internal contacts on the selector switch tend to corrode over time and cause erratic readings. As a temporary measure, note the position of the switch, then rotate it back and forth several times. This helps clean the contacts in the switch. Note that some switches have to be pushed in slightly first before they will rotate so don't force it. Return the switch to the original position, then run the engine to see if that helped.

If it works, the fix can last for years or not long at all. Chances are it'll happen again as it's an indication that the components inside the gauge are starting to degrade and you should budget for new replacements.

Keep us posted

Thank you sir.