90 hp johnson questions?

[invaded86]

Just bought my first boat, 1986 invader with a 90hp Johnson v4. while cleaning and otherwise just inspecting the engine I noticed one of the temp wires was unclipped from the harness. the other is connected to the harness. I cannot find where the other wire clips into. I do see another black wire with the same style clip that is unplugged but its not the same color? is there any way to test this or am I missing something simple.? thanks in advance

 

[invaded86]

I just traced the black wire that is unplugged and looks to be for the oil tank. I'm guessing the low oil alarm? when looking at the wiring harness there are 2 wires, tan, that are clipped to each other, port side just below the unplugged temp sensor. when grounded they sound an alarm at the control box. on the starboard side of engine if I ground the clips for that temp sensor the alarm sounds. I'm not worried about the vro as from the advice of our local marine engine mechanic it will be removed. however I would like to hook the temp sensor up the correct way. I can post pictures if anyone would find that useful?

 

[Bosunsmate]

The sensors ground out when overheated hence completing a circuit to ground in your contol box with the horn having positive feed already to it.
So you just need to connect both sensor tan wires to the ones to the horn. There is normally a rubber sleeve at the connection to stop them grounding out there
And that is a good decision to premix and not use vro

 

[invaded86]

thanks for the reply. The part I am having trouble with is where is the missing wire that should connect the port side sensor to the horn. my starboard side is hooked up and working but the port side is just dangling. I will post the picture I took when I get the chance later on. that might shed some light on what im seeing.
Thanks.

 

[Bosunsmate]

I cant remember if there are two separate wires leading to the control. Someone on here should know. If not you can just join the dangling port side over to the starboard one, so a overheat on either will activate that wire. That is if the sensor is working.
You should put in a new water pump if you arent sure how old/used the current one is

 

[invaded86]

here is what I am seeing on the port side. wires in left hand are connected together and when grounded set off the alarm.

 

[Bosunsmate]

Yes connect those two ends together, they kind of interlock by latching over each other and then slide that rubber tube in your right hand over the connected metal parts and you a done

 

[Bosunsmate]

On many models when you turn the key on (before you got to start) the horn will let off a little buzz to let you its working. I often touch that metal connection to ground before i go boating to check that the wire to the horn still works too. Unfortunately, as i said earlier, i know of no way to test the sensor itself

 

[invaded86]

The picture is a little iffy at best but the wires in my left hand are connected to one another. leaving the sensor wire on its own. last night I unclipped the 2 wires from one another and hooked the sensor to one of the ends. tested by grounding and got an alarm. It looks to me like someone left the oil tank alarm wire unclipped from the "extra" wire. No idea why but the oil alarm is a non point as it wont be used in the near future. so now I have both sensor wires connected and functioning. . . as long as the sensors are good lol.
​thanks for the replies. I often find forums the best place to learn when getting into something new.

​The boat itself is in good condition, interior is great for its age. the motor seems to run well, a little bit stumbly at trolling speed but I'm curious to see the difference with a new set of plugs and bypassing the vro. the plugs look fouled and oil saturated but we have no clue when they were done last.

​On another note I have located the impeller rebuild kit on this site and plan on doing that after the weekend.

 

[invaded86]

ok so I thought it was "that simple" I took the 2 wires, both tan, and dis-connected from one another, I then hooked the port side temp sensor to one and tested function by grounding. It sounds the alarm when grounded. so the sensors are wired to the horn at least and the horn works. next I took the un clipped tan wire that goes to the horn and connected to the vro oil tank line and the alarm sounded but would not stop. . . the other side is already grounded to the block completing the circuit and causing the alarm. ??? so what am I missing. I know the horn wire has to be connected to the tank and I know that to complete the circuit it must be grounded. I'm thinking it was disconnected for faulty alarm? any thoughts or test methods?

 

[Bosunsmate]

you need to run premix fuel until you a sure it is only a faulty alarm, check oil level goes down in correct usage amount

 

[invaded86]

Im certainly using oil, it goes down in the tank a considerable amount every time we go out in it. Im not sure how to judge how much it is supposed to use but in the last 2 outings ive used half a tank of fuel and 1/4 of the oil tank.. or more. . . maybe someone can nail down the usage for me or point me in the direction of where to find it.

 

[invaded86]

also it is 1 constant alarm which if I understand correctly is an overtemp alarm? it only alarms when connected to the oil tank?

 

[invaded86]

1 more thing, the alarm sounds with the engine NOT running and the key in the on position. hope that helps clarify.
Thank you!

 

[Fed]

The switch in the bottle is not a straight out on/off switch, it has it's own little brain that only closes every 30 seconds to produce a chirp.
My 90 bottle oil level drops about 20mm or so for every 50 Litres of fuel used.
You can convert to your little gallons.

 

[invaded86]

so the switch in the tank should not sound continuous when hooked to the alarm system is how im taking that. lol the conversion works out to be for every 13 gallons of fuel you consume there is a drop in the oil tank of just over 3/4".

 

[Fed]

Yeah that's it, 13 little gallons or 11 real gallons.

Sounds like you have a bad switch or the switch wiring is shorting to ground.
Safe to disconnect so long as you keep the bottle topped up until you convert to pre-mix.

 

[invaded86]

im very much on the fence about the conversion. our local marina mechanic said to do it as it can be done in minutes but the motor will smoke a lot more at idle and trolling speeds. i like the safety of pre mix as i will not have to deal with the worry of faulty wiring or possible engine failure. any thoughts. there is more content on here on the vro topic than i know what to do with.

 

[Fed]

I'm on the fence too, I have been running a 1988 VRO2 for the last 10 Years but I could easily convert simply for peace of mind.
It's a mental problem, good luck!

 

[ondarvr]

I like oil injection, but your motor is old enough that removing it is probably a good idea.

This isn't to scare you, but those motors tend to break rings, so if for some reason that happens it's not because you did, or didn't remove it.