115hp mercury 1999 4 cyl inline no fire on 2 cyl

modsrx

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my motor don't have fire on a 4 plugs ...only have fire on 3 and 4 ...it look to be a stator issue anyone can help me on it ??

..I know all coil are good if I switch the 2 top coil for the 2 bottom one they work but always no fire on cylinder 1 and 2 something is not charging the coil or don't trigger them :confused: I replace a stator on a johson for a similar problem..not sure if they have problem on them...some people talk about 2+2 merc how do I know if its a 2+2 ..maybe its normal but doesn't want to idle ???
 
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achris

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

Your engine is a 2+2... All the 4 cylinder loopers are. The 2+2 feature shuts the FUEL to the bottom 2 cylinders right down, very low, not enough to fire (but still enough to lubricate those 2).... Spark remains on all 4 cylinders.

If you have lost spark to 2 cylinders, that usually indicates a trigger failure or a stator. The easiest way to test the stator is to just swap the connectors at the stator end (the grn/wht and the wht/grn)... If the fault moves to the other 2 cylinders, you have a faulty stator, if it stays, then the trigger is the problem...

Chris.....
 

canoemang

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

I think with a 2+2 the carb on 3 n 4 don't have a idle jets.. i think they still spark though..

Im not 100%..
 

modsrx

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

Your engine is a 2+2... All the 4 cylinder loopers are. The 2+2 feature shuts the FUEL to the bottom 2 cylinders right down, very low, not enough to fire (but still enough to lubricate those 2).... Spark remains on all 4 cylinders.

If you have lost spark to 2 cylinders, that usually indicates a trigger failure or a stator. The easiest way to test the stator is to just swap the connectors at the stator end (the grn/wht and the wht/grn)... If the fault moves to the other 2 cylinders, you have a faulty stator, if it stays, then the trigger is the problem...

Chris.....

I switch those 2 wire and the problem didn't move ...does the trigger come with the stator ...that would explain the reason why it work on choke and then die cause the 2 lower carb don't have idle jet
 
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achris

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modsrx

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

thnx ok the trigger is the one who give some timing advance .... sorry about that question loll..is it a parts that fail often ??
 

achris

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

thnx ok the trigger is the one who give some timing advance .... sorry about that question loll..is it a parts that fail often ??

That's right. The trigger is moved/rotated by the linkages with the carbs... And that advances and retards the timing... I wouldn't say it was something that failed 'often', but it's not unheard of..

Don't worry about asking so many questions... a, that's what we are here for, and b, if you don't ask you'll never find out... ;)

As I tell my trainees... Better to ask a thousand questions than make one screw-up because of not asking questions.....

Chris.......
 

modsrx

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

thnx I will order a crank tigger and hope this will solved the problem ........I was not sure about the stator or trigger but with your help it look to be the trigger :p ..thnx and thnx
 
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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

If this motor has CDM's don't think that stator is your problem nor triggers...

10.05.2013-19.38.png


10.05.2013-18.54.png


Depending on your experience with a multimeter the second diagram may help or not good luck!
 

modsrx

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

If this motor has CDM's don't think that stator is your problem nor triggers...

10.05.2013-19.38.png


10.05.2013-18.54.png


Depending on your experience with a multimeter the second diagram may help or not good luck!



so it mean eatch coil got a diode inside of them ??if a diode is bad it will screw up the firing ?? im good with a multimeter is it what u try to tell me ??
 

modsrx

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

so it mean if I change coil of place the problem should change place
 

achris

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

so it mean if I change coil of place the problem should change place

Exactly... And you said you already did that, so back to the parts that didn't move....
 

modsrx

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

I remember went I move the coil of place the coil that didn't fire did but not at the same place ...maybe I got something wrong with coil ...the more I think the more it make sense
 

achris

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

Start your testing again if you have any doubts.
 

modsrx

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

yes I will :p thnx for your help that really help me ..probalbly save me some money too
 

CharlieB

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

Unplug one and test for spark on the other 3, then unplug 2 and test the other three, unplug 3 and test for spark on the other three, etc.

One way you will get spark on the three remaining with the bad one unplugged.
 
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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

If you have CDM's yes (not switch box)? You have CDM's if you have 4 wires going to each coil.

10.06.2013-11.09.png
 
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Dave1027

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

I am not so sure this OP has an ignition issue. He says "it works on choke". I got a feeling he has fuel delivery issue like maybe fuel pump or carbs.

OP, you first need to verify if you have a working ignition system like with a spark gap test or simply try a timing light on all four spark plug wires. Don't do any assuming. These 2+2 motors idle on the top two cylinders and "kick in" the bottom two at about 1800 RPM. That is normal operation and it's done strictly by carburation like another poster said, the bottom two have very little idle fuel. Just enough to lubricate but not enough to fire.
 

modsrx

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Re: 115hp mercury 1999 4 cyl inline no fire on 2 cyl

I am not so sure this OP has an ignition issue. He says "it works on choke". I got a feeling he has fuel delivery issue like maybe fuel pump or carbs.

OP, you first need to verify if you have a working ignition system like with a spark gap test or simply try a timing light on all four spark plug wires. Don't do any assuming. These 2+2 motors idle on the top two cylinders and "kick in" the bottom two at about 1800 RPM. That is normal operation and it's done strictly by carburation like another poster said, the bottom two have very little idle fuel. Just enough to lubricate but not enough to fire.


I know its spark issue not fuel issue ..it run on choke cause it feed the bottom carb and I think the bottom carb doesn't have any idlel jet .....it doesn't spark on 2 top cylinder It seem those engine run on the top cylinder at idle ...
 
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