Emergency starting strings - Page 2

Matt · 16 November 2007, 21:36

As a kid, I used to regularly accidently run a merc 50 with the battery disconnected - passenger would catch their leg on it and switch the battery off. Never did any harm since it was an unregulated bridge rectifier, and the ignition ran off the other coil. My old 150, later xr2's, anc checking the V6 merc book, the rest of em of a similar era too, were all the same.
(Although unsure whether efi motor would have continued running.)

Nevertheless, obviously NOT suggesting anyone knowingly disconnect their battery with regulated alternators - will probably get expensive.

Matt · 16 November 2007, 21:39

Actually my point is traditional motos don't need a battery since the ignition runs directly off the stator. You could create a superlight weight V6 with no battery or starter.

They actually had 3 circuits, high speed, low speed & charging.
The favourite that stumped me for ages was losing the high speed circuit - motor would run great up to 2500 rpm, then fall flat.

Quote:

Originally Posted by ian parkes

Thats about it and as Mat says . I remember that bike , the battery was knackered just a dull glow from the ignition light not even a click from the solonoid . However it did Kick/ Pull start and just about got me a mile down the road before it died completely . That is my point your battery could be shot and unable to take any charge but giving enough to allow you to pull start it , then the motor will stop after a few miles and you have had it .
Its worth turning off the battery just to see what system you have. After all battery or conection of ,is the most likely failure in a boat thats bouncing about .

Nos4r2 · 16 November 2007, 21:42

Quote:

Originally Posted by ian parkes

Thats about it and as Mat says . I remember that bike , the battery was knackered just a dull glow from the ignition light not even a click from the solonoid . However it did Kick/ Pull start and just about got me a mile down the road before it died completely . That is my point your battery could be shot and unable to take any charge but giving enough to allow you to pull start it , then the motor will stop after a few miles and you have had it .
Its worth turning off the battery just to see what system you have. After all battery or conection of ,is the most likely failure in a boat thats bouncing about .

That situation assumes the charging system can't chuck enough power out to charge the battery-or the battery is pulling more power out than the charging system can give.

As long as it's only your battery that's nearly dead or a bad contact replicating it then your engine should carry on running indefinitely once started as it'll be supplying it's own power-even if it can't increase what's in the battery. Don't let it stop though.

Rogue Wave · 16 November 2007, 21:42

Quote:

Originally Posted by Matt

Careful, I am a hardboater after all.

Good info considering.

Quote:

Originally Posted by Matt

The favourite that stumped me for ages was losing the high speed circuit

now you're just getting carried away.

Matt · 16 November 2007, 21:48

Yeh, you're right. It really pissed me off.
I sound like a right old fart sometimes.

Rogue Wave · 16 November 2007, 21:54

Quote:

Originally Posted by Matt

I sound like a right old fart sometimes.

Join the club.

Matt · 16 November 2007, 21:56

No, I just sound like one.

Rogue Wave · 16 November 2007, 22:05

Quote:

Originally Posted by Matt

I just sound like one.

You smell like one as well

Matt · 16 November 2007, 22:06

alystra · 18 November 2007, 16:16

Quote:

Originally Posted by ian parkes

I was about to start a thread on this subject . I was wondering the other day when my battery switch played up just how easy it is to start a 100 ish HP with a rope and what size motor is the max .

Also how many motors these days keep running when the battery power is lost ?

Well, I'll try to answer your question. Anchored in the middle of nowhere for the night. Accidentally left ignition on and P & S nav lights on. Next morning even the vhf woudn't switch on. Panic.

Took the hood off, wound the string and pulled - hard. So hard in fact that I fell over because it wasn't difficult at all - and the engine was running, just like that.

Year 2000 Merc 4str 90hp. It has a separate ignition coil from the charging coil.

9D280 · 19 November 2007, 12:51

Yeah, old 2- strokes with separate ignition & batery charging coils will start & run no problem. I dunked the battery switch on the old boat (don't ask!) and the Suz ('93 DT25) ran for a week as a pull start machine, even with the CDI.

Needless to say I ended up using spare handlheld VHF for the tail end of the week, and on the new boat the switch is above toob height on the assumption if the water is higher than that, a corroding switch will be the least of my worries......