1990 90 HP Johnson

[Bassnwhaler]

Hello all! Love this forum. I just purchased this motor and it runs like a top. I never get any kind of alarm or sound when I crank. I did find some wires disconnected so I connected them. Now when I turn key on I get a instant horn. From my digging and J Reeves posts it seems I may have a faulty sensor (for the engine overheat) and would love some help as to how to correct this issue. I would like all the alarms working for obvious reasons, especially as everyone seems split on the idea of removing the VRO. (It was repacked with a new system 10!years ago and seems to be working properly. I don’t want to go into that question at the moment but just looking for how to get my alarms hooked back up and properly functioning. Any and all help is most appreciated.

Thanks,

Bassnwhaler

 

[flyingscott]

What color were the wires that were disconnected?

 

[Bassnwhaler]

Tan to black. Port side. Black wire runs directly out of motor to the boat.

 

[Bassnwhaler]

[No message]

 

[Chris1956]

Tan is likely the overheat alarm wire. Black is usually ground. They probably should not be connected. I would recommend you get a wiring diagram and see what you have connected.

On a lot of models, Tan overheat wires (1 form each cylinder head) should connect to powerpack, via a diode. They should also connect to a horn/light. When the overheat sensor detects overheat, it grounds, sending that ground signal to powerpack and horn/light. That causes horn to sound and/or light to illuminate, plus causes the powerpack to limit RPM.

 

[Bassnwhaler]

Awesome info. I assumed it connected to the black wire because that is the only other wire not connected and is located perfectly to connect. Goodness knows what the previous owners did. I’ll look for a wiring diagram and start to eliminate variables. Thanks for the direction

 

[jakedaawg]

The blue crimp on the blk wire is not original. Is it by chance a pair of wires that run to the remote oil tank?

 

[flyingscott]

I agree with the above those look like oil tank wires.

 

[havoc_squad]

I agree with the above those look like oil tank wires.

I suspected that being the case as well.

Hopefully the gas tank is mixed with 50:1 TCW-3 and oil injection capped off or converted pre-mix only fuel pump.

I might recommend doing a compression test on that motor before going any further. If the VRO wasn't hooked up right long enough, might have done some damage by the previous owner or this startup if the gas didn't have 50:1 pre-mix as a fail safe for a "new to me" motor.

Not saying the motor is junk prematurely, just check compression first before throwing hundreds of dollars on repairs.

 

[Bassnwhaler]

The thing is the motor is running well. Pushes my 19’ Sea Nymph GLS at 39mph WOT (5700 rpm) and cruises well at 31 mph at 4900 rpm. I can’t imagine it has compression issues but will check that to be sure. My main concern is knowing the alarms will function properly if something does go wrong.