mercruiser alpha one 4.3 turns over will not fire

jeraldm

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Feb 23, 2015
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just bought this boat its a 1992 maxum it has the mercruiser 4.3 alpha one, i took the boat out and it was running great i backed off the throttle and it died and now it won't start back up it has fuel and I'm getting spark to the distributor but not getting any spark to the plugs what should i do and check without going out and buying a bunch of parts i dont need does anyone have and suggestions thanks
 

alldodge

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just bought this boat its a 1992 maxum it has the mercruiser 4.3 alpha one, i took the boat out and it was running great i backed off the throttle and it died and now it won't start back up it has fuel and I'm getting spark to the distributor but not getting any spark to the plugs what should i do and check without going out and buying a bunch of parts i dont need does anyone have and suggestions thanks

:welcome: to iboats

Do you have an engine serial number?
 

bilge rat jim

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Jun 28, 2012
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330
Remove the distributor cap and check the condition of the cap and rotor contacts.-------The cap and rotor kit from SM is part# 18-5274, about 25 bucks.
 
Last edited:

jeraldm

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Feb 23, 2015
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hi i do not have the engine serial number at this time the boat is located at a friends house 1 hour away at the moment i will try and have him get it for me tonight
 

Bondo

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Remove the distributor cap and check the condition of the cap and rotor contacts.-------The cap and rotor kit from SM is part# 18-5274, about 25 bucks.

Ayuh,..... Agreed,.... The spark goes from the coil tower to the distributor, 'n out to the plugs through the rotor,....

Welcome Aboard jeraldm,.... Pull the distributor cap off, 'n see why the spark ain't comin' out,.....

If it's corroded up terminals, 'n rotor,....
Scratch the crud off with a screwdriver tip or something, 'n Try it,.... for Testin' purposes,.... ;)
 

wrench 3

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Aug 12, 2012
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2,108
If you have a good spark going into the distributor and no spark at any of the plugs, the rotor is most likely shorting out to the distributor shaft. Some times you can see were it's shorting through and sometimes you can't.
 

JASinIL2006

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Feb 10, 2012
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5,524
If you have a dead man's switch at the helm, make sure it wasn't bumped accidentally into the off position.
 

Fun Times

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When you pull the distributor cap off, crank over the engine by using the ignition key to ensure the distributor shaft/rotor is turning. Also be sure the rotor is on tight and there isn't a lot of free play/movement anywhere by hand.
 

jeraldm

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Feb 23, 2015
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4
thanks everyone i just took at the connections and cleaned everything up to the coil and distributer and it fired right up i appreciate all your time
 

Watermann

Starmada Splash of the Year 2014
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Jan 12, 2013
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13,747
I hope that was the easy fix. Did you try starting the motor again before going through and cleaning the ignition parts? I can't remember the exact name of the sensor part that's in the distributor that I've had to replace before that caused me an instant no start condition and then out of the blue it would fire off again after a day or 2. It's the part the 2 wires connect to going in the distributor. It just concerns me that there was no running rough condition prior to the no start condition if it were just corroded connections.

Just thinking outloud here because I hate to see happy boating adventures turn into frustration and embarrassment... trust me I know all about both.
 
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