Yamaha wiring ?

redxpuser · 28 March 2010, 08:55

Hi,
I have recently purchased a mid 80's 28hp Yamaha 2 stroke outboard. It is electric and manual start, but has a few wiring problems.
It has a loom with a home made 'ignition key' consisting of just a 2 piece plug which is pushed together to engage the starter.
Although it starts easily, I have no way of stopping it !
Is there anyone who can tell me which wires go where as I need to add a new ignition ?
Also, which wires are needed to add a remote stop on lanyard please?
Thanks to all.

Nos4r2 · 28 March 2010, 09:28

Quote:

Originally Posted by redxpuser

Hi,
I have recently purchased a mid 80's 28hp Yamaha 2 stroke outboard. It is electric and manual start, but has a few wiring problems.
It has a loom with a home made 'ignition key' consisting of just a 2 piece plug which is pushed together to engage the starter.
Although it starts easily, I have no way of stopping it !
Is there anyone who can tell me which wires go where as I need to add a new ignition ?
Also, which wires are needed to add a remote stop on lanyard please?
Thanks to all.

White and black (earth). Join the 2 to stop the engine. Works for stopping it on the killcord as well as the ignition.

How many ignition coils does it have? Is it one with 2 outputs or 2 separate ones? Once I know which engine it is, I'll post a wiring diagramme for it. No point in giving you the wrong one.

Poly · 28 March 2010, 09:29

This might be of some use:

Or you can get many Yamaha manuals to (view only) at the Yamaha US site.

Nos4r2 · 28 March 2010, 09:37

Quote:

Originally Posted by Polwart

This might be of some use:

Or you can get many Yamaha manuals to (view only) at the Yamaha US site.

I think that's a fourstroke diagramme

Oil pressure switch is a giveaway.

redxpuser · 28 March 2010, 09:40

Thanks Nos,
Here's a picture of the engine which should help you with ID.
Can you see the two wires (red and black) that have been twisted together - any idea what these are for ?
Thanks,
Andy

redxpuser · 28 March 2010, 09:46

One other thing, while trying to stop the engine, I accidently pulled the lower of the two HT leads off, and managed to break the lead - is it an easy fix ?

Nos4r2 · 28 March 2010, 09:55

Are you 100% sure that's a black and not a filthy yellow with tape on? It definitely shouldn't have a red twisted to it if it's a black.

Diagramme is attached.
Ignition switch should be wired as per the 2nd diagramme.

Nos4r2 · 28 March 2010, 09:57

Quote:

Originally Posted by redxpuser

is it an easy fix ?

Depends where you've broken it. Is it that the cap's come off? Looks like it in the pic. If so, just buy a new cap from a bike shop and screw it on.

Poly · 28 March 2010, 10:00

Quote:

Originally Posted by Nos4r2

I think that's a fourstroke diagramme

Oil pressure switch is a giveaway.

Yes - but the control box end of things (ignition, stop, kill etc) is the same across all the Yamahas. Not sure how far back in time that goes or if they've changed the colours at any point. I read it that he already had the wiring loom in place - just nothing connected at the control box end? However I hadn't seen your earlier post.

Quote:

One other thing, while trying to stop the engine, I accidently pulled the lower of the two HT leads off, and managed to break the lead - is it an easy fix ?

I doubt it. Even if you can bodge together a repair - I would be woried about it would fail randomly whilst at sea.

redxpuser · 28 March 2010, 10:02

Thanks again Nos - will try and sort it out today, have to find a suitable ignition switch first.
Thanks, Andy

p.s. Finally moved away from playing with the Mercury Blue/red bands, hope this motor will give me less grief !

Nos4r2 · 28 March 2010, 10:07

Quote:

Originally Posted by redxpuser

Thanks again Nos - will try and sort it out today, have to find a suitable ignition switch first.
Thanks, Andy

p.s. Finally moved away from playing with the Mercury Blue/red bands, hope this motor will give me less grief !

It should do-it'll go like the clappers on your flatacraft too. Are you putting remotes on it?

This'll do the job:-

http://cgi.ebay.co.uk/yamaha-outboar...item1c114c19dd

Nos4r2 · 28 March 2010, 10:11

Quote:

Originally Posted by Polwart

Yes - but the control box end of things (ignition, stop, kill etc) is the same across all the Yamahas. Not sure how far back in time that goes or if they've changed the colours at any point. I read it that he already had the wiring loom in place - just nothing connected at the control box end? However I hadn't seen your earlier post.

Fair-it'd do the job if there weren't random wires twisted together. I think the loom wants properly checking all the way through though.

Quote:

Originally Posted by Polwart

I doubt it. Even if you can bodge together a repair - I would be woried about it would fail randomly whilst at sea.

Ditto. Unless it's just a new HT cap, get a new coil. HT joiners aren't much good and in a marine environment I really wouldn't want to rely on one.

redxpuser · 28 March 2010, 10:12

Thanks Nos, I'll buy that one straight away !

Regarding the two twisted wires - just had a look and they are two RED wires twisted together, coming from the back of the throttle. Don't know what they do though ?

Nos4r2 · 28 March 2010, 10:18

Quote:

Originally Posted by redxpuser

Thanks Nos, I'll buy that one straight away !

Regarding the two twisted wires - just had a look and they are two RED wires twisted together, coming from the back of the throttle. Don't know what they do though ?

It's a live of some sort from the battery-join them properly.If it's not properly insulated, you may have a fire on your hands or blown fuses. You'll need to check back with the diagramme to see what they are hooked up to.

Regarding that switch, you should have the right colour codes on that to match the wiring diagramme.

redxpuser · 28 March 2010, 10:24

Just checked - it is a red wire from the rectifier to the starter relay - should have had an in-line fuse fitted, but obviously been removed, probably due to fuse failure and no spare.
I will put in a new in-line holder and re-connect properly.
Diagram doesn't show fuse rating though - so best guess scenario !

Poly · 28 March 2010, 11:37

Quote:

Originally Posted by redxpuser

Diagram doesn't show fuse rating though - so best guess scenario !

I think mine is 20A if I remember right. I'll be going to move the boat between sheds in the next few days so will check then. Its on a 20HP 2 cylinder 2str, electric start, no power trim so sounds like the "loads" will be similar to yours.

redxpuser · 28 March 2010, 11:48

Thanks for that Polwart, sound like that will be fine - 20A it is then !