Jump starting a i/b with my o/b...a good idea??

brother chris

Commander
Joined
Jul 28, 2002
Messages
2,063
I was out on the lake on Sunday....just as I was pulling away from the dock...maybe 20 feet away....I was getting the good old feeling of fishing...then I hear this guy yelling from the dock. I turn to look and he asked me if I could drive him across the lake to jump start his boat. He left his blower motor on overnight and killed both his batteries.
I says sure...it'll only take a couple minutes.
We get there and this guy has an i/b 350 (or something like that). We tried starting his boat just hooking up the jumper cables to the batteries...no go, even after waiting 5 minutes.
So buddy suggests that I start my motor and that will help his battery get some more juice so his motor can start. I hummed and hawwed for a minute...thinking it was not such a good idea. BTW...I have a 1978 55hp evinrude.
So we start my motor and let it run for a couple minutes, then he tries to start his boat...nothing...it won't start. So I tell him that I'll just disconnect my battery and he can put it in his boat. At the same time, my motor starts to sputter and dies. I tried to start my motor again to no avail.
Luckily my buddy was there in his boat too...he had an extra battery so he just let the guy use his battery.
I pushed away from his boat so I could figure out why my motor won't start. It turns over but no coughing or anything...it just turns over and over
After checking the fuel line and everything I could think of, I go and look at the lower powerpack and notice that there is a slight hairline crack in it.
My buddy tow me back to the dock.

So does anyone think that it is not a good idea to jump start an i/b with an o/b motor. Did I wreck my power pack by doing this?
(Hmmm....wondering if I should be posting this in SHT's)

Now I've to figure out if I wrecked anything else on my motor...ugh!!!


Oh and it was my birthday that day too.....what a day!!!
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Jump starting a i/b with my o/b...a good idea??

You didn't disconnect your battery while the engine was running did you? NEVER do that!
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: Jump starting a i/b with my o/b...a good idea??

happy birthday, bro!

The other battery was drained to the point of no return - let 'em get below 10.5 volts or so and they're ready for the recycle bin.

What I know about DC electricity, you can't break your powerpack by adding more 12V batteries in a parallel circuit. But I'm pretty much a hacker when it comes to electrics.

What if the other guy had his batteries combined with a switch or something and was messing with it, and connected 'em in series momentarily.....ok I'm just grasping at straws.......hope your motor's ok.
 

brother chris

Commander
Joined
Jul 28, 2002
Messages
2,063
Re: Jump starting a i/b with my o/b...a good idea??

Thanks guys.
After checking my book, I stand corrected...it is the #2 ignition coil which is cracked...not the powerpack as I stated before.
We tested my friend's ignition coil last month...while he was turning it over, I tapped the coil (lightly) with a screwdriver handle and it started, but it would not start if you did not tap the coil (we saw a hairline crack on the coil) We replaced the coil and it runs perfect. Hopefully it will be that easy for me too!
B.C.
 
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