Mercury electric problem

eula30 · #1 April 7th, 2003, 07:10 AM

Hi, I have a mercury 50hp 1985 4 cylinder 2 stroke. Model # 1050625 and Serial # A133393. The problem is in spark plug number 2. (No spark) (Coil, sparkplug and sparkplug cable are good they wore tested) (Compression on the cylinder is between 117 to 122 in all 4 cylinders) Now there is a cable coming down from the stator to the power pack and from the power pack to the number 2 coils I think thatÂ’s where the problem is. I need to test the cable that comes down from the stator to the power pack to see if is any power on that cable and donÂ’t know how to do that or what the voltage on that cable. If there is power on that cable then I think the power pack may be bad and if is no power on that cable then maybe the problem is on the stator or in the cable it self. Any advice on how to test these cables please and what is the voltage they should reed? I really want to test the cable for power before changing the stator or the power pack. I really appreciated any help.

Thank you.

graddy · #2 April 7th, 2003, 07:23 AM

Disconnect all the wires from the switch box that go to the stator. Red/white blue/white, blue, red. Red volt meter lead, to red wire, black volt meter lead to ground, should see 200-300volts. Red to red black to ground 20-90 volts. Bolth test are done at cranking speed with a well charged battery. The violet, white, brown, white/black lead are your trigger, you should see 1-3 volts at cranking. If all test good and you checked alll the grounds than it could be a SCR switch in the switch box.

eula30 · #3 April 7th, 2003, 07:36 AM

Thank you. I will do that today.

Thank's

dstuard · #4 April 7th, 2003, 08:48 AM

DTS - Am I reading your post correcly. Looks like the same test. Should one say red to red and white? I am about to do these myself.

graddy · #5 April 7th, 2003, 09:24 AM

I'am sorry the the test should be red volt meter lead should go to the blue stator lead, black meter lead to engine ground.200-300 high side of stator.

Red stator lead should go to red meter lead and black meter lead to engine grond. 20-90 volts. low side of stator.

Bolth tests done at cranking with well charged battery.

dstuard · #6 April 7th, 2003, 11:12 AM

Thanks. That makes sense to me now.

eula30 · #7 April 7th, 2003, 07:14 PM

Hi, I did test the cable that comes from the stator to the power pack. I test the high voltage and the low voltage and all the wires coming from the stator tested ok. Now the cables that go from the power pack to the coils I tested them also and only one cable did not have any power on it. This cable goes to coil witch is the coil that I didnÂ’t get any spark. Now my question is if I get power from the stator to the power pack but only one cable going from the power pack to the coil. There is power going to the power pack from the stator and from the power pack to the coil except for one. Does this mean I have a bad power Pack?

Thanks

eula30 · #8 April 8th, 2003, 09:20 AM

Hi, if there is power going in to the power pack from the stator and there is power going from the power pack to the coils except one (Green & white)with out any power. Is that means that I have a bad power pack?

Thank you

dstuard · #9 April 8th, 2003, 11:08 AM

http://www.outboardparts.com/mercury...eshooting2.htm

This might help. It helped me a little.

graddy · #10 April 8th, 2003, 11:20 AM

There is not test for the switch box. You have to test everything around the switch box and if everything passes then you have a bad switch box. Stator test good, trigger is good, coil test good, ground are checked. Next is a switch box.

dstuard · #11 April 9th, 2003, 12:26 PM

Does the stator have to be working to test the trigger? Just curious

dstuard · #12 April 9th, 2003, 06:49 PM

dstuard · #13 April 10th, 2003, 09:11 AM

What does a dva meter do that a dcv and acv meter does not?

Paul Moir · #14 April 10th, 2003, 10:48 AM

DVA also measures (A)mpheres. The (D)igital part implies an input impedance of 10Mohms. Low current voltage sources that are measured with a normal analog meter (~100kohms) will excessively load the source giving inaccurate readings. Sorta like checking tire pressure with a giant pressure gauge - the guage deflates the tire excessively. (V)accum (T)ube (V)olt (M)eters' (for those who remeber them) are the exception. Digital meter's usually have better ranges (esp. low ohms) and obviously better precision. Accuracy is usually about the same (dollar for dollar).

dstuard · #15 April 10th, 2003, 10:55 AM

So I have to get a DVA adapter if I am to get an accurate reading? I am pretty dumb when it comes to all this. Will I be able to do the test? I can follow the steps if they are lined out in my manual. (If it ever comes in)