Beware yanmar key start

[dslittle]

Started engine as normal on Sunday. Cast off and after about 100 yards the battery alarm started off. Returned to pontoon and shut down engine. Checked voltages and engine battery showing 11.9v. Strange as had been on shore power with charger on for weekend. Turned off batteries and turned on again. Domestic bank showing 12.9v and engine battery still 11.9v. Checked batteries - no apparent issues. Noticed electrical burning smell from engine bay. Checked alternator but appeared fine. Checked starter motor. IT HAD BURNT OUT. It looks as though the key had not returned to the on position from the start position and the starter motor had remained engaged and burnt out, obviously generating large voltages in the 12v system.

I am now waiting for another starter motor to arrive to fit and then check how much/if the 12v system has been damaged.

No issues in previous eight years. Arghhh

 

[RichardS]

It is not that unusual with boat engines and we have had the same issue raised before.

I suspect that it is not an issue with car diesel engines because the silencing is much better and you would hear the starter motor running.

Richard

 

[westernman]

Been there. Done that.

In my case the key chain had too many keys on it which caused the bunch to get stuck with the start motor engaged. In my case I had flames coming out of the thing.

I immediately shut down the engine - which meant of course it could not be restarted.
Ended up sailing into port.

Which is terrifying - particularly with an inexperienced crew.

 

[mjcoon]

I suspect that it is not an issue with car diesel engines because the silencing is much better and you would hear the starter motor running.
Richard

I had something similar with my car's petrol engine. Eventually took the ignition switch apart to lubricate it but still obsessively ensure the key returns from starter position...

Mike.

 

[Sybarite]

Hope your problem is sorted out now Dave.

 

[pugwash01]

Any idea why it got stuck?

 

[dslittle]

In my case the key chain had too many keys on it which caused the bunch to get stuck with the start motor engaged.

I immediately shut down the engine - which meant of course it could not be restarted.

Why did it happen? I really can't comment as my wife started the engine (which is unusual) but the reason above would give me food for thought!!! I think that I will start up in future.

BTW the 'two keys' have been on the same ring for eight years without an incident...

 

[pugwash01]

Is it at all possible that Mrs. Little inadvertently turned the key back to the 'off' position while the engine was running?

 

[dslittle]

Is it at all possible that Mrs. Little inadvertently turned the key back to the 'off' position while the engine was running?

No names please it is still sub judice...
That is possible but the outcome would suggest that it was more likely jammed in the start position. Oh well lesson learnt.

 

[westernman]

Is it at all possible that Mrs. Little inadvertently turned the key back to the 'off' position while the engine was running?

Does not hurt. At least it seems not to, and I have been there and done that as well (well not me, but one of the crew).

 

[pugwash01]

I would have thought you're right about 'no harm' from turning off. There is some suggestion that the 'nickel' coating on the key flakes off in time and can jam the key.