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Mercury 75 4 stroke spark at sparkplug but no ignition (2&3) cylinder

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primzy

Member
It is 2003 mercury 75 4 stroke, 4 carbs.
What can that be (video). You can hear spark jumping from cable to sparkplug, but nothing.
Carbs were cleand
Fuel filter and lines were replaced
New sparkplugs

 
Also noticed I have a voltage regulator probleme. Its charging 16.5V.
I am about to disconnect it and try, can it be responsable for problem like mine?
 
racerone said:
Time to visit your local boat repair shop
Click to expand...
Is this a joke?
I see you are a gold medal contributor, and I hope that not all your posts are that bright... sorry, dont want to insult you, because I do not know you. But this is a boat repair forum so all threads can end in one post, go to your local boat repair shop...
First changing plugs on 2 and 3 cylinder makes no logical sence, at least I did not get one...
Can you explain why time to visit repair shop has come now?
Thank you
 
Right now I assume thete might be a problem with throttle position sensor, because it does not make any reaponse when turning manualy. Anyone fammiliar with this?
I also disconnected recitifire, no changes...
 
primzy said:
Is this a joke?
I see you are a gold medal contributor, and I hope that not all your posts are that bright... sorry, dont want to insult you, because I do not know you. But this is a boat repair forum so all threads can end in one post, go to your local boat repair shop...
First changing plugs on 2 and 3 cylinder makes no logical sence, at least I did not get one...
Can you explain why time to visit repair shop has come now?
Thank you
Click to expand...
With Internet advice, many times the information you receive will be worth exactly what you pay for it.
 
So position sensor magicali started working, or wasnt bad at first.
I corrected position of it, because timing was a bit out, now its like it should be. Engine runs better.
Still sometimes I get spark and sometimes no. Checked it with strobe, and by pulling caps off.
Now it bothers me, that #3 wasnt geting spark and #2 did get.
Both signals come from same ignition coil.
Also #2 has much stronger spark
 
If this is so , then you have valve/cam problem. Have you checked plugs to see if gap was mashed closed? Did it strat this after or before carbs cleaned?
 
faztbullet said:
If this is so , then you have valve/cam problem. Have you checked plugs to see if gap was mashed closed? Did it strat this after or before carbs cleaned?
Click to expand...
We are tallking about 5° off timing. No, gaps are fine.
Actualy boat wasnt able to go above sometimes 2200, sometimes 4000rpm. So I cleaned carbs. Before cleaning I thought sparks were fine, checked it and at that time they were sparking.Problem is, that as soon I hit wave and boat shakes it stopped working propperly (running on 2 or 3 cylinders).
 
Is it possible that i am having this problems because of bad stator? I measured 1.4ohm insted of 0.7ohm on all wires (like manual suggest). I know 1 Ohm is almost nothing.
I noticed with strobe light that I get blink when I am checking the wire to ignition coil. After ignition coil the blink is inconsistant.
Is is posaoble that stator doesnt provide enough electricity to create a strong spark later?
 
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