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Author Topic:   Jump starting an outboard
dino54904 posted 08-03-2009 03:34 PM ET (US)   Profile for dino54904   Send Email to dino54904  
If the 12v battery on my Whaler is dead can I jump start it from my car using jumper cables like I would if I were jumping another car?
Buckda posted 08-03-2009 03:38 PM ET (US)     Profile for Buckda  Send Email to Buckda     
Depends on what motor you have...but generally speaking, yes.

I would recommend pull-starting your motor (up to 100 hp) if that is an available option. Modern outboards have expensive and sensitive electronics, and improperly jump starting in such close proximity to those electronics would make me wary.

Another alternative is to use one of those emergency battery booster packs that mechanics often have - that might give you the juice you need to let the motor charge the battery via the alternator or charging output current.


dino54904 posted 08-03-2009 04:16 PM ET (US)     Profile for dino54904  Send Email to dino54904     
Motor is an early 90's Johnson 150 VRO.
jimh posted 08-03-2009 08:44 PM ET (US)     Profile for jimh  Send Email to jimh     
Jump starting an engine seems like an unnecessary risk that the electronics could be damaged, and unless it were an emergency situation, I would not do it. Instead, I would remove the battery from the boat, put it on a charger, slowly recharge the battery, and when it was restored to 100-percent charge, test the battery on a load tester to evaluate it.

If the battery is not in near-perfect condition, I would replace it. On a boat at sea there is little room for marginal batteries which may not start an engine, and it is just silly to scrimp on the battery and put yourself at risk.

My assessment of the risk and reward factors of jump starting a dead battery:

Risk: damage expensive electronics on motor, perhaps costing $500 or more to repair or replace.

Reward: avoid a few hours of charging or a new $75 battery

My assessment of the risk and reward factors of using a marginal battery:

Risk: motor will not start in perilous situation, perhaps causing tragic harm.

Reward: avoid buying new $75 battery.

In both cases, the reward is minimal and the risk is great.

You should also discover what caused the battery to become discharged to the point that it cannot start the engine. In normal operation, it is very unusual that the main starting battery cannot crank over the main engine. Something must have gone awry to cause the battery to become discharged. That needs to be remedied.

dino54904 posted 08-04-2009 09:19 AM ET (US)     Profile for dino54904  Send Email to dino54904     
Thanks Dave and Jim. With that said I believe that it would be fair to say that carrying a set of jump cables on board in the case of a dead battery situation would not be as good of an alternative as carrying a small recharger and extension A/C power cord. Correct?

At times when my son uses the boat he leaves it with the battery switch on BOTH and the electronics on. When I then return a few days later to use the boat you know what I find... Training and the posting of a storage check list don't seem to be working real well.

Chuck Tribolet posted 08-04-2009 09:30 AM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Jump it right and no problem.

Start donor.
Connect both negative sides.
Connect both positive sides. After you hook up the first
positive side, be VERY careful not to short anything.
Run donor at fast idle (1500-2000 RPM) for several minutes.
Drop donor back to normal idle.
Start recipient.
Run both donor and recipient at fast idle a couple of more
Disconnect positive sides.
Disconnect negative sides.

You do need to figure out why the battery is flat, and whether
It's been ruined by having been flattened.


Buckda posted 08-04-2009 09:38 AM ET (US)     Profile for Buckda  Send Email to Buckda     
Very simple solution to your problem.

Next time, after it happens - when the request is made for the keys, withold them.

It won't take too many times (perhaps only once) before the lesson is learned. A boat is just too fun of a toy for a kid not to do things by the book.

When my dad let me borrow his stuff (i.e. his cottage with a bunch of college buddies) we were extremely careful to clean up and take care of it because in my family, if you don't take care of things, you don't get to use them.

Ask my do you get 5 college guys to sweep, clean the bathrooms, wipe down the countertops and sinks and generally walk the thin line for the last 4 hours of a trip?

Offer them another chance to use it in the future if they take care of it. Make it clear that the offer will not be extended if they don't.

My dad sure got smart between the time I graduated High School and when I graduated from College. He must have taken night classes while I was in school...

dino54904 posted 08-04-2009 09:52 AM ET (US)     Profile for dino54904  Send Email to dino54904     
Buckda...I think both of our fathers went to the same night school. Seems like while I was getting smarter in college he was getting smarter at home. Go figure.


TransAm posted 08-04-2009 04:10 PM ET (US)     Profile for TransAm  Send Email to TransAm     
Invest in a battery booster pack that Dave suggests. I have one and rarely leave the dock without it. They plug into a regular outlet to re-charge and hold a charge for several weeks or longer. In addition, they typically contain a 12v receptacle, a light and a air compressor. All for about $50 at a big box store. I jump-started a fellow att he gas station the other day and he insisted on giving me a $20.
HAPPYJIM posted 08-04-2009 04:29 PM ET (US)     Profile for HAPPYJIM  Send Email to HAPPYJIM     
I'm going to over ride what Chuck says to jump start it. It is the order of clamping to the batteries that should be done this way.

Connect the Positive (+) terminals first. Them connect the negative (-) donor or good battery next. No circuits have been made yet. Connect the last negative(-) to a bolt on the engine. The reason to do this is that it stops the chance of a spark igniting the gases given off from the battery. I have seen a battery blow the caps off and get acid in my friends face and eyes. I throw water on him real quick but it was not pretty. After connecting the jumper to the bolt, let it set for a few minutes to charge the dead battery. Give it a chance to build up a little charge before cranking. Once you get it started disconnect in reverse order. Naturally, make sure all other electrical devices are switched off before jumping anything. This procedure works for any other vehicles, cars, trucks or tractors.

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