MerCruiser 4.3 wont start! HELP PLEASE!

leo319

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Sep 11, 2010
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Any help will be much appreciated, thanks in advance!
 
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dubs283

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

well, you got two out of three - spark, fuel, compression - should run

are you sure you have spark??

if you do have spark coming from the coil tower, then by all means you should have spark going to the wires - pull the cap and check the rotor/cap - broken parts??

might be weak/intermittent spark too - possible ignition sensor problem - if its never been replaced, do it - it will eventually fail
 

ChrisCraftJohnny

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

That purple wire that you speak of is for the electric choke on the carb.
 

dubs283

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

electric choke circuit wire is purple/yellow

purple/white is for putting the ignition control module into service mode - this is done by grounding the wire to set timing/idle speed
 

leo319

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

got it to work guys thanks so much and i apologize for replying so late... The problem was inside the distribuitator... i took it apart and i found a broken rotor...(so relieved it was something that simple :)) Now i have a different problem with water in the oil but i just created a new thread for that, hope you check it out...Thanks again folks!

I still cant find the choke on this boat, does it even have one on the boat? I kinda had issues turning it on when cold but i figured i had to give it some throttle to turn on faster... i guess ill create another thread once i fix the oil thing..hahaha.. alright guys, thanks...peace..
 

Alpheus

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

You have a choke.

What kind of carb do you have???
 

leo319

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

here is my carb...
 

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dubs283

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

i see the choke!

the plate that is above the two barrels that rotates open and closed is the choke plate

on a cold engine it should be open like in the picture - pump the throttle once and the plate will close all the way - one more pump of the throttle and crank the engine over - should start

once the engine is running the electric circuit will heat the bimetal coil in the choke assy (stbd side of carb - round and black) and the plate will slowly open as the engine warms up
 

leo319

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

so youre saying i can control the choke with the throttle by pumping it before starting the cold engine?

ok, thats good to know if i understood right. i was expecting a button/switch or something similar to activate the choke.
 

dubs283

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

so youre saying i can control the choke with the throttle by pumping it before starting the cold engine?

you can set the choke (close the plate) with the first throttle pump, thats it - there is no "controlling" the choke with the throttle otherwise

try it, you will see how it works

ok, thats good to know if i understood right. i was expecting a button/switch or something similar to activate the choke.

manual chokes on cars/boats are a thing of the past - they are basically "automatic" now
 

leo319

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

haha..i guess ima little old school then.. thanks a lot... will keep that in mind and definitely will use now on..
 

Alpheus

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Re: MerCruiser 4.3 wont start! HELP PLEASE!

If you are old school then you should know your supposed to give the gas a couple of pumps on a cold engine with a carb. Its in your owners manual...
 

leo319

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Sep 11, 2010
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Re: MerCruiser 4.3 wont start! HELP PLEASE!

i understand. i was just looking more for a choke button type of thing. thanks for the help.
 
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