89’ Sundancer tach, temp gauge, and shifting issues

[impy03]

Hello everyone!

My name is Eddie and I am brand new to the forum and just purchased a 1989 Sea Ray 280 Sundancer with 4.3l Mercruiser V6s and bravo 1 out drives. I took my maiden voyage over the weekend to move the boat from one marina to another and ran into a few issues that the seller had made me aware of prior to purchase.

1. The starboard engine tachometer bounces around and just overall does not read anything close to the port engine tach. Both motors cranked and ran fine from what I could hear the entire 30-40 minute trip duration.

2. The starboard engine temperature gauge is also not reading correctly. It was not bouncing around or reading high, rather it was not registering any temperature at all which made me very anxious the entire trip to say the least.

3. The starboard engine throttle/shift cable seems to be stiff and is clunky when shifting into gear. I noticed that the engine RPMs also seemed to be a bit higher immediately after going into gear and it was hard to shift it back to neutral compared to the port engine.

Could all 3 issues be somewhat related since they are all connected to the starboard engine? Should I start with the instrument panel first? Do I need the throttle cable to be replaced?

Any and all help is most appreciated!

 

[Espos4]

They are probably not related.

The tachometer has a switch on the back. Move it back and forth and reset it to the appropriate position for your 6 cylinder engine.

The temp gauge issue could be a thermostat stuck open, a bad sending unit, or defective gauge.

Shifting issues may be from a stiff cable. Disconnect it from the shift mechanism at the motor and see if the handle moves easier.

 

[impy03]

Thank you for the quick and prompt reply, Espos4.

I plan on heading to my marina this coming weekend to dismantle the instrument panel, since I also need to replace a few 2-way toggles that are giving out. The first thing I will do is adjust the tachometer switch and check the terminals for a loose connection. Would it be a good idea to just start by replacing the temp gauge if the connections look good?

Where in the world can I cross reference a older part number? The original part number I have for the temp gauge is a 127795 teleflex.

Thanks again!

 

[Espos4]

Take the wire off of the temp sending unit on the thermostat housing. If you have 2 sensors, it’s the 1-wire sensor that feeds the dashboard temperature gauge.

With the ignition on, Ground that wire. The temp gauge should go to full hot. If it does, I’d say that the gauge is good.

 

[impy03]

Espos4 - Thank you for all the help, I've since fixed the shifting and high RPM issue. It seems the idle speed screw on the carb was adjusted way too high and that was causing the issue.

I took apart the dash and tried adjusting the switch for the tach and it seems to be working a bit better, but still floats around some. I ran out of time and have not yet tested the temp gauge, but that is next on my list this week. Thanks again!