Jumpstarting

Cruzomatic

Petty Officer 3rd Class
Joined
Aug 30, 2005
Messages
78
Hi, is the principal of jumpstarting boat to boat the same as road vehicles? This weekend, I was flagged down by two boats that both needed jumps. Neither one of them started. Just wondering if we were doing something wrong?Thanks,
 

Boomyal

Supreme Mariner
Joined
Aug 16, 2003
Messages
12,072
Re: Jumpstarting

What do you mean, "Neither one of them started"?<br /><br />That covers a lot of territory. If it is simply a dead battery, a good set of jumpers that will carry adequate current, positive to positive, negative to negative and Vrooom. If not, something else is wrong. Doesn't matter whether it's a car or boat.
 

Cruzomatic

Petty Officer 3rd Class
Joined
Aug 30, 2005
Messages
78
Re: Jumpstarting

Neither of the two boats that I helped out started up. One of them was an inboard ski boat, the other an i/o runabout. The first one (ski boat) wouldn't even turn over. The second (i/o) seemed like it flooded out. Reason I ask this is because, while one of them was cranking away my RPM gauge would spike up a bit without me touching my throttle. I thought for sure it wasn't good for my engine, especially being it was only my third time on the water with it. Yeah, I think they both had more than just battery trouble as we did have the cables connected neg to neg, pos to pos. Just thinking maybe I shouldn't have had my engine on at idle.
 

Baldguy

Petty Officer 2nd Class
Joined
Sep 30, 2001
Messages
174
Re: Jumpstarting

Connecting Neg to Neg and Pos to Pos is not the proper way to jump start a vehicle from what I've been taught and read.<br /><br />The neg jumper for the bad vehicle should be connected to a good ground (engine block) not the neg terminal. Using this method, you will not even have to have your engine running in order to "jump" the other vehicle.
 

coleman kayak1

Petty Officer 1st Class
Joined
Aug 8, 2005
Messages
260
Re: Jumpstarting

Baldguy, you are right. But I prefer to hook +/+ -/- because i don't want to have to worry about finding a good ground, especially on a boat
 

murphini

Petty Officer 2nd Class
Joined
Jun 17, 2004
Messages
116
Re: Jumpstarting

I bought one of the "Portable Jumpers" to take with me for just such a reason. Only had to use it once, but much easier than getting two boats next to each other. Can spend $39-69 for those at most auto shops.
 

jtexas

Fleet Admiral
Joined
Oct 13, 2003
Messages
8,646
Re: Jumpstarting

baldguy, I agree with vehicles, but my understanding is that is done so if any sparks fly they'll be away from the battery, to reduce chance of igniting whatever gas it is that batteries produce. electrically speaking, you make the same circuit since the batt is grounded to the vehicle frame. Connected to batt or frame or engine block doesn't affect whether your engine is running or not.<br /><br />that said, be aware when making the connection on the boat battery, sometimes they do throw sparks - just don't move it around on the terminal any more than ya have to.<br /><br />sounds like you got it right, cruzo, and did the right thing coming to the aid of disabled boats.<br /><br />and welcome to iboats!
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Jumpstarting

Jump starting a marine engine is no different than jump starting a car or truck. However, let's understand what happened to cause the problem. Chances are if the battery just "went dead" as most operators would contend, they weren't paying attention to the voltmeter or ampmeter on their vessel. Chances are one or more of the following happened. 1) Battery simply went to battery heaven (its shot), 2) Alternator quit and operator didn't notice the voltmeter dropping, 3) accessories ran too long with engine off, 4) other electrical malfunction. In any of these scenarios (except for #3) chances are that even if the engine did start by jumping, it won't stay running because there is simply not enough juice in the dead battery to keep it going. Besides, an alternator failure would not put juice back into it. If an engine will not turn over by jumping, chances are the battery is simply shot. It will not take a charge and cannot be jumped. What needs to happen in that scenario is to remove the positive cable from the dead battery, then connect the positive jumper to the removed cable. However, this must be done with another available battery (trolling motor or jump start unit for example). If the engine still doesn't crank, there is another electrical problem.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: Jumpstarting

The "stay running" statement after jumping applies to engines that require the battery to run. Most outboards do not.
 
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