Yamaha 70 wiring

Roflhat · 17 June 2015, 14:18

Hi,
Anyone know about wiring on these?
I'm going tiller control and pull start only, so a lot of the wires will be obselete I think. I have no idea which ones I need/don't need or where they need to go. I'll be needing the kill cord on the tiller.
If anyone can point me in the right direction I'd really appreciate it.

These are the ones leaving the engine to the controls:

Theres a yellow, green, white, red, brown, blue and black. That's about as much as I know about wiring!

The one on the left here I think is the limiter (covered in red tape), grey wire coming from the CDI box

Cheers

spartacus · 17 June 2015, 19:38

Wiring... don't you just love it.

Yamaha wiring is the same the world over. Yamaha have a specific tiller with the gear selector and kill switch integrated and should simply connect to your wiring loom on the engine. I sold a 40V (6H4) tiller that was like this as I was hooking up to remotes.

...........................................

WHITE Wire - Engine Stop/Kill.

When this wire is earthed, it stops the engine. There may be more than one switch on tiller control models that connects to this wire.

For Example: The Engine Safety Kill Switch has one wire attached to earth and another attached to the WHITE Wire, Should you fall from the boat taking your Safety Lanyard with you, when the lanyard disconnects it either releases a switch to make contact or pulls a switch down to make contact. When this switch makes contact it connects this WHITE wire to earth which stops the engine.

BROWN Wire - Engine Start
When this wire is supplied with a positive charge it triggers the Starter Solenoid which in turn supplys 12 Volts to the Starter Motor to turn the engine over.

BLUE Wire - Engine Choke/Prime
When this wire is supplied with a positive charge it opens the valve on the Choke Enrichener or Creates a Electro-Magnetic field and engages the Mechanical choke mechanism.

PINK Wire - Warning System
This wire is connected to the Warning Horn, The warning horn has a constant 12V Feed from the purple wire (Ignition Live) whilst the engine is turned on, if a Temperature Switch or the Oil Level Sender makes contact due to the engine overheating, oil too low or simply a faulty sender the horn will sound.

YELLOW Wire - Ignition Live
This wire is the Ignition Live, it supplies 12Volts with the Ignition Switch in the On Position, it supplys the warning horn and dashboard gauges.

GREEN Wire - Tachometer Signal
This wire is the Sender (AC) For the Tachometer (Rev Counter)

Black Wire - Earth (Neutral)
This wire is Connected to the Engine Earth / Battery Negative.

RED Stripe Wire - 12V Positive
This wire is connected to the 12V Positive Supply from the battery

SKY BLUE Wire - TRIM UP Switch
This wire supplies positive to the Trim Relays when the Trim button is pressed up on the control box handle

LIGHT GREEN Wire - TRIM DOWN Switch
This wire supplies positive to the Trim Relays when the Trim button is pressed down on the control box handle

Roflhat · 17 June 2015, 20:24

Thank you very much! That's exactly the information I was after.

So with pull start, no trim, no battery etc. Where should I connect each wire?

Rough action plan
Pink wire - leave alone
Blue wire - remove, going to try and make a manual choke mechanism
Brown wire - remove
Yellow wire - remove
Green wire - remove (using a tiny tach)
Black wire - Shorten and use an earth on the engine
Sky blue wire - remove
Light green - remove

Red stripe wire - can I remove this? I have no battery. Or do I connect it somewhere else to provide voltage to the coils?

White wire - leave alone, see if I can make the killswitch work

Seem like a reasonable plan? Thanks for the help

spartacus · 17 June 2015, 22:08

Are you fitting a genuine Yammie tiller? The part you need is 62Y-W0086-Z0-40 which fits 2-strokes 40-90hp. It will come with the throttle and gear linkages, and importantly the wring loom, so it's literally plug and play.

Roflhat · 18 June 2015, 07:15

Yeh I've got a genuine yamaha tiller on it, unfortunately it's a newer style one, which pushes the throttle open, whereas the engine needs a pull to open cable. So I'm looking to swap my new tiller for an older style one which I can modify to work.

The one I have will work, just when I twist the throttle to speed up it will slow the engine down and vice versa, will take some getting used to

Roflhat · 18 June 2015, 12:37

Removed a lot of the electrics today, starter, solenoid, electric choke, rectifier and lighting coils all gone. Going to try and get hold of a manual choke mechanism.

wiring looks a lot less intimidating with everything removed, thanks for your help!

Roflhat · 18 June 2015, 16:29

Anyone know which bits I need to get the cables to work?
Here's what I have at the moment, the small clip fits over the cables

Thanks again

Davie · 18 June 2015, 17:47

Been watching this thread on here and on mad. Why dont you anchor the inner cable to the block of the engine and attach the outer cables to the throttle arm? It will work but you will need to fabricate a load of bits but you need to keep the cables as long as possible or you will not be able to tilt the tiller arm. You will not be able to do what you work the throttle in reverse as you propose as the tiller kit will not let you select gears at full throttle which is what you will be trying to do.

Roflhat · 18 June 2015, 22:37

Quote:

Originally Posted by Davie

Been watching this thread on here and on mad. Why dont you anchor the inner cable to the block of the engine and attach the outer cables to the throttle arm? It will work but you will need to fabricate a load of bits but you need to keep the cables as long as possible or you will not be able to tilt the tiller arm. You will not be able to do what you work the throttle in reverse as you propose as the tiller kit will not let you select gears at full throttle which is what you will be trying to do.

Hi Davie,
interesting idea, dissapointed I didn't think of that myself! haha
I see what you mean about changing gear as well, I hadn't anticipated that. The easiest way is definitely to get another tiller, which I can modify.
Cheers

Davie · 19 June 2015, 05:39

Phone Hindle controls.. They will make you a longer cable that you can route around the powerhead and will solve your problem.

Roflhat · 29 July 2015, 08:16

tiller has now been modified so that the cables push/pull the right way. But the cables are now too long by around 60mm, so I need to order shorter ones. going to give Hindle controls a call and see if they can help

Nightfisher · 28 August 2015, 09:22

Inspite of receiving some great information above re wiring, removing any of the charge or lighting coils may or may not be the best avenue, I feel. Actually I wouldn't mess with the wiring at all for the mods your doing without a complete Service manual in hand and some knowledge of all the do and don't do specifics. The only advantage I see based on your stated mods is you can sell the parts removed for a handsome price. Hand starting a 70 is no easy task on a engine-moody day. Good luck.

Roflhat · 29 August 2015, 08:54

Thanks,
all the wiring is now done, got the engine going but still fine tuning it. I took the lighting coils off, I'd done the same on my tohatsu 50 before. It's fairly straightforward, the idea being to reduce electromagnetic drag on the engine and thereby squeeze another 0.01hp out of it!
re starting it, I know now haha! My hands are cut and bruised from pulling it over hundreds of times this last week, wishing I'd left the electric start on until it was tuned...

Nightfisher · 29 August 2015, 09:39

Quote:

Originally Posted by Roflhat

Thanks,
all the wiring is now done, got the engine going but still fine tuning it. I took the lighting coils off, I'd done the same on my tohatsu 50 before. It's fairly straightforward, the idea being to reduce electromagnetic drag on the engine and thereby squeeze another 0.01hp out of it!
re starting it, I know now haha! My hands are cut and bruised from pulling it over hundreds of times this last week, wishing I'd left the electric start on until it was tuned...

That size engine won't notice a thing in removing lighting coil. The only difference will be 14 lbs from engine weight (starter). How did you manage moving the electric choke to the cowl or base?

Roflhat · 29 August 2015, 21:10

Probably not but it's one less part to go wrong!
I removed the electric choke controls, the engine has a hole cut in the lower cowl for the choke linkage. I'm just using a length of wire for the linkage just now, theres a choke connection on the bottom carb, it's an on/off choke which clicks into position.