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Dominick
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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I have a 2006 mercury 4 stroke ..the motor runs but will not

Customer Question

i have a 2006 mercury 4 stroke ..the motor runs but will not put the boat on plane..has a vibration in it . i had a 12 deg prop went to 10.5..i also picked up an electronic tach. what we noticed when switching from the top spark plug wire to bottom.. the the tach would be twice as much.. full out top cyl was 4200 and bottom was 2100 approx..
Submitted: 8 months ago.
Category: Boat
Expert:  Charles replied 8 months ago.
Hello, my name is***** will assist you. So that I get the correct diagrams, would you post the serial number of the engine?
Customer: replied 8 months ago.
1b301986
Expert:  Charles replied 8 months ago.
Thanks, ***** ***** removed the plugs and inspected them yet?How big is your boat?
Customer: replied 8 months ago.
its a 14 ft remote i had checked with mercury prop selection...fo the weight and type of boat it recommended a 9x10.5 and approx speed would be 23 it goes 9 will check plugs in a sec
Customer: replied 8 months ago.
plugs look fine not wet nor carbon ed up
Expert:  Charles replied 8 months ago.
Do you have a multimeter to test them?
Customer: replied 8 months ago.
yes how to test
Expert:  Charles replied 8 months ago.
Are the plugs DPR6 EA9 ?
Customer: replied 8 months ago.
yes
Expert:  Charles replied 8 months ago.
Set your meter to resistance, hold one of the meter leads against the boot end of the electrode, take the other meter lead and touch the threads, you should get no reading at all, A spike and a drop, is still a reading. Then move the meter lead from the threads to the end of the electrode, compair the two plugs, are they close in readings?
Customer: replied 8 months ago.
the electronic tach measures the pulses to the plugs.....?
Expert:  Charles replied 8 months ago.
coming from the coil yes, but being as it is so far off, I am thinking you have a bad plug. Both cylinders should read the same.
Customer: replied 8 months ago.
both plugs are the same
Customer: replied 8 months ago.
the previous owner said thats how it ran from new....low power
Expert:  Charles replied 8 months ago.
Have you even done a compression test on it?
Customer: replied 8 months ago.
no
Expert:  Charles replied 8 months ago.
I would recommend that you do one before we get too far into the engine. Need to see what it is that you are working with.
Customer: replied 8 months ago.
ok will do
Expert:  Charles replied 8 months ago.
Make sure that you use the warm up throttle to get the butterfly open in the carb. Otherwise the numbers will be really low.
Customer: replied 8 months ago.
i guess we will have to wait on this i need to get a adapter for the gauge the thread size is too small
Expert:  Charles replied 8 months ago.
Yes it is 12mm on this engine. Tomorrow perhaps?
Customer: replied 8 months ago.
yes i will pick one up...is there anything eletronic that regulates the spark to the pistons
Expert:  Charles replied 8 months ago.
Great, my son has a baseball game tomorrow night, and I will log on after that. I have a day job also and do this in my sparee time in the eve and on weekends. Talk to you then.Charles
Customer: replied 8 months ago.
good luck to your son
Mike
Expert:  Charles replied 8 months ago.
Thanks Mike.

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