Yanmar 6LYA STP won't start

[Cartouche]

We have a 2002 Mainship 390 with a Yanmar 6LYA STP engine, engine would not start, was in neutral, Played with the shifter, and then starter engaged, and Started fine, Shut off and started right back up, is this a starter issue or another issue, Many thanks for any help

 

[Ski in NC]

Probably just the neutral start. Close, but not quite in neutral.

 

[Pau Hana]

Check the neutral start switch- if it’s sticky, it will exhibit the signs you experienced.

 

[LN-RTP]

Been there done that with my 6LP-STE, no start, no nothing.
I knew it was not the neutral switch because I installed a new throttle/shifter and ignored the neutral-safety hook up, Besides, I always shut down and start in neutral, duh..

After hours and hours troubleshooting and replacing start relay etc, somebody suggested I move the throttle/shifter and she started right up...
(The tranny has a separate idiot switch, independent of the throttle.)
Had to eat humble pie that day..

 

[Cartouche]

Check the neutral start switch- if it’s sticky, it will exhibit the signs you experienced.

Where is this and what am I looking for Many thanks

 

[LN-RTP]

Where is this and what am I looking for Many thanks

Not sure where, but look at the transmission, you should see 2 wires.
I will look at mine today and let you know.

 

[DavidM]

Not sure where, but look at the transmission, you should see 2 wires.
I will look at mine today and let you know.

I can't recall any shift switch on my Yanmar 6LY with a ZF 220 transmission. So I think it is part of the throttle/shift lever mechanism.


David

 

[Cartouche]

I will check the throttle shift leaers

 

[Cartouche]

I have Identified it is the switch in both helm controls not sure wether it is the switch or the lobe on the shift lever depressing the switch does anyone know where I can find either

 

[DavidM]

Can I lend you my wrenches?


David

 

[Cartouche]

Why is it really hard to take apart

 

[LN-RTP]

. I can't recall any shift switch on my Yanmar 6LY with a ZF 220 transmission. So I think it is part of the throttle/shift lever mechanism.

I got the ZF tranny and pretty sure there is a switch down there, if not, then on the fuel control unit: Can’t start out of idle, or out of neutral.
I replaced the dual throttle/shifter with the 2 levers a year ago with a single lever
Teleflex/Morse unit. No electric wires going up there but instructions and connectors for hooking it up, figured I was not protected..Wrong.

Turns out there is a Yanmar or ZF switch somewhere down in the engine room providing the same protection.
Did not have a chance to look today, but will do tomorrow.

 

[Cartouche]

Many thanks

 

[LN-RTP]

Sorry I am late responding.
Yes, there is 2 wires going straight to the transmission on my boat.
Did not shoot a picture, but a quick look on your part should find the same.
I assume the wires are for the neutral switch, otherwise an over temp sensor, not sure.
Been busy working on boat stuff between rain showers, friends in town, wife and dog, forgot this thread and my promise to show and tell.
If you don’t see the wires on your tranny, let me know and picture is coming.

 

[Cartouche]

Many thanks no all is good, it was the neutral switch in the shifter controls had worn, I replaced the whole lower unit and moved it to the flybridge, and she starts flawlesley from both helms.