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 225hp Mercury - won't run if battery cables are disconnected
#3497443
05/23/09 02:44 AM
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Joined: May 2004
Posts: 323
sh26
OP
Angler
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OP
Angler
Joined: May 2004
Posts: 323 |
Is that normal? I can start the motor then disconnect the battery cables and the motor dies.
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Re: 225hp Mercury - won't run if battery cables are disconnected
[Re: sh26]
#3497538
05/23/09 03:12 AM
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Joined: Dec 2003
Posts: 3,180
2-stroke
TFF Team Angler
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TFF Team Angler
Joined: Dec 2003
Posts: 3,180 |
It's normal with most outboards for the rectifier/regulator to burn out when you unhook the battery while it's running, but that doesn't shut 'em off. Does your motor have an electric fuel pump? It won't be getting power after the rectifier fails, if there's no battery there.
Battery-driven CDI's were fairly common on outboards back in the 60's, maybe into the 70's.
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Re: 225hp Mercury - won't run if battery cables are disconnected
[Re: 2-stroke]
#3497563
05/23/09 03:19 AM
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Joined: May 2004
Posts: 323
sh26
OP
Angler
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OP
Angler
Joined: May 2004
Posts: 323 |
I think it has an electric fuel pump but it dies pretty quick. Could it be the alternator?
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Re: 225hp Mercury - won't run if battery cables are disconnected
[Re: sh26]
#3497742
05/23/09 04:21 AM
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Joined: Dec 2003
Posts: 3,180
2-stroke
TFF Team Angler
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TFF Team Angler
Joined: Dec 2003
Posts: 3,180 |
Outboard alternators in general don't tolerate running while unhooked from a battery very well, sorry can't say for sure about yours in particular. measuring the battery voltage while the motor's running would tell you if it's working -- should read more volts than when it's not running.
carbed or DFI? or EFI?
what year?
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Re: 225hp Mercury - won't run if battery cables are disconnected
[Re: 2-stroke]
#3498109
05/23/09 12:36 PM
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Joined: May 2004
Posts: 323
sh26
OP
Angler
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OP
Angler
Joined: May 2004
Posts: 323 |
It is a 2001 EFI. One other thing that seems to be going on is something seems to be draining the battery while in storage for a week or so. This is my second battery and it is brand new, I thought the other was bad but I guess it was not. I think this is all related somehow, just no clue.
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Re: 225hp Mercury - won't run if battery cables are disconnected
[Re: sh26]
#3498137
05/23/09 12:58 PM
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Joined: Feb 2002
Posts: 6,039
flexpress
TFF Celebrity
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TFF Celebrity
Joined: Feb 2002
Posts: 6,039 |
I found the same dead batt .put your ear to the boat see if you here anything running .My auto belige pump would be onn with power switch off. un hook and replace the switch is bad .
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Re: 225hp Mercury - won't run if battery cables are disconnected
[Re: flexpress]
#3507303
05/26/09 07:55 PM
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Joined: Dec 2003
Posts: 3,180
2-stroke
TFF Team Angler
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TFF Team Angler
Joined: Dec 2003
Posts: 3,180 |
If you have a multimeter with a fuse-protected input, you can pinpoint the source a parasitic drain by hooking up your meter in series with the (-) battery cable, and pulling fuses one at a time, watching for the current to drop out. If you have more than one ground lead on the battery, combine them for this exercise. Or you could use the positive battery leads, doesn't really matter.
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Re: 225hp Mercury - won't run if battery cables are disconnected
[Re: 2-stroke]
#3508099
05/27/09 12:09 AM
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Joined: Aug 2007
Posts: 4,591
stick steering
TFF Team Angler
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TFF Team Angler
Joined: Aug 2007
Posts: 4,591 |
as jt said you most likely fried the rectifier, now you need to look at the stater, any leaking in and around the flywheel from the stater that you can see
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Re: 225hp Mercury - won't run if battery cables are disconnected
[Re: stick steering]
#3509596
05/27/09 11:36 AM
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Joined: Sep 2001
Posts: 5,442
don the angler
TFF Celebrity
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TFF Celebrity
Joined: Sep 2001
Posts: 5,442 |
Here is a dumb question. Why do you disconnect the battery with the motor running? Are you testing something?
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Re: 225hp Mercury - won't run if battery cables are disconnected
[Re: don the angler]
#3509978
05/27/09 02:12 PM
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Joined: May 2003
Posts: 12,334
PGR Mike
TFF Guru
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TFF Guru
Joined: May 2003
Posts: 12,334 |
Don't disconnect the battery while the engine is running. You can easily be buying a $2500 ECM in a hurry!
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