Rigging for twins - what are the basic principles?

[Markus]

I have a lot of switches to play with on the dashboard of my Skater, and they can be put in a lot of different combinations shutting various things on and off. I have therefore had a lot of fun trying to figure out what each switch switch does.

E.g. there is a switch that kills the entire starboard side of the boat, engine and corresponding gauges.
When trimming up, both engines move together. When trimming down, they move individually.
Ignition on both engines has to be on in order to to start (or at least to start the starboard engine).

While there must be some guiding logic behind the whole thing, e.g. being able to synchronize as well as not synchronize the engines, I am really struggling with understanding it.

What are the basic principles / best practices when rigging twin engines?
__PRESENT

[PanRonnie]

it,s in the back off every manual
on my boat every engine is a complete separate system start key gauges alarm horn
with a double dead man switch so 4 switches 2 on both sides
the charging systems can be synchronised by battery select switches
if your dashboard trim switches are original they are probably dual on one switch so the systems are also seperate

[keefallan]

Markus, how good are you with trouble shooting electrical stuff? You may get stuck with tracing wires and ringing them out with a meter. There's really no reason for them to be synched at all.....the engines. The only thing you would want to be(needs to be) synched is the kill switch and the trim for safety reasons at high speed. But you should also be able to separate the motors for trimming individually as well.....like a switch that has left ,right, and both selections. But on my dads 26 footer, the trims were separate as well.....a factory installation. But unfortunately, the only thing to tell you, if you cant figure out what you have.............a meter and tracing out wires.

I look at it like this. Those motors are completely separate and they should be except for the kill switch(s)(lanyards if that be the case). and possibly the trimming if it makes it safer at high speed. But if the trim is linked, there should be a selector switch to be able to isolate the trim units if necessary. In my head, I cant think of any other reason to link them at the helm. The only thing that should link them at the helm is safety issues. You should be able to start and stop them by themselves.........either one. You should be able to start the starboard motor by itself without touching anything relating to the port motor and vice versa. Even the neutral safety switches dont have to be linked.

[flabum1017]

When you say both ignitions have to be on to start the starboard engine, do you mean with the port ignition off, the starboard will spin but not start or it won't even spin? If it will spin and not start, then there is a shorted diode in the lanyard switch harness. As for them not both trimming down, then there is an open diode on the side that won't trim down in the trim handle harness.

[Markus]

When you say both ignitions have to be on to start the starboard engine, do you mean with the port ignition off, the starboard will spin but not start or it won't even spin? If it will spin and not start, then there is a shorted diode in the lanyard switch harness. As for them not both trimming down, then there is an open diode on the side that won't trim down in the trim handle harness.

I think it would not even spin. E.g. not a lanyard issue. But I will check next time I play with the boat.__PRESENT

[Markus]

Markus, how good are you with trouble shooting electrical stuff? You may get stuck with tracing wires and ringing them out with a meter. There's really no reason for them to be synched at all.....the engines. The only thing you would want to be(needs to be) synched is the kill switch and the trim for safety reasons at high speed. But you should also be able to separate the motors for trimming individually as well.....like a switch that has left ,right, and both selections. But on my dads 26 footer, the trims were separate as well.....a factory installation. But unfortunately, the only thing to tell you, if you cant figure out what you have.............a meter and tracing out wires.

I look at it like this. Those motors are completely separate and they should be except for the kill switch(s)(lanyards if that be the case). and possibly the trimming if it makes it safer at high speed. But if the trim is linked, there should be a selector switch to be able to isolate the trim units if necessary. In my head, I cant think of any other reason to link them at the helm. The only thing that should link them at the helm is safety issues. You should be able to start and stop them by themselves.........either one. You should be able to start the starboard motor by itself without touching anything relating to the port motor and vice versa. Even the neutral safety switches dont have to be linked.

Thanks! Very helpful.

Having run 260s, I am pretty good at troubleshooting anything electrical or mechanical.

On Sunday, I was crawling around with an ohm-meter, trying to figure out why the starboard side was dead no matter the battery setting. First culprit was the battery selector, but it was alright. Then we found an unmarked switch, and it woke up. That's why I am asking for the general principles.

The stuff you describe is exactly the kind of info I need.__PRESENT

[Markus]

it,s in the back off every manual
on my boat every engine is a complete separate system start key gauges alarm horn
with a double dead man switch so 4 switches 2 on both sides
the charging systems can be synchronised by battery select switches
if your dashboard trim switches are original they are probably dual on one switch so the systems are also seperate

What about jack plates? Are they separate, too.__PRESENT

[PanRonnie]

If you have them yes
I bolted the engines straight to the transom
The 3 or in my case the middle hole

[keefallan]

Marcus, if you find double pole, double throw switches in the wiring, those are the ones to pay attention to if they are unmarked. Those can be used in so many ways and be used as a selector switch........on/off/on stuff...............and I am glad I could help a little.

[keefallan]

PanRonnie..........nice homemade water boxes for the outboards...........thumbs up on that!! How long does it take to fill?

[PanRonnie]

PanRonnie..........nice homemade water boxes for the outboards...........thumbs up on that!! How long does it take to fill?

yeh made that for the noise but also helps with the backpressure so you can set the idle better at home
but filling yes takes a couple of coffee runs

[Markus]

I'm getting there.

Realized that the switches tend to be grouped vertically. Big insight.

Figured out which switch toggles right versus left versus both jack plates. (But first brought out the multi-meter, because it seems like a relay was dead)

Also found the trim switch that bumps the starboard engine in or out in case engines get out of sync.

Main thing that puzzles me now is the bilge pumps.

__PRESENT

[FUJIMO]

...can tell by the rigging, it was done many years ago...oldie but a goodie...

[PanRonnie]

Very proud and honoured to own this boat