No Spark - Mercury 50hp 4cyl serial # A133985

[scottpellegrin]

How do I test the switch box and the stator? Ran fine one day and no spark on all 4 cylinders the next.

 

[Barnacle_Bill]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

For starters disconnect the black/yellow wire at the switchbox then recheck for spark. If you now have spark there is a problem with your kill circuit which includes a mercury switch, wiring, emergency kill switch and ignition switch.

 

[Barnacle_Bill]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

In case you didn't know that is a 1985 model.

 

[Laddies]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

Here's the test, the only wat to test a switch box is by checking input and output voltage

 

[scottpellegrin]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

Thanks

 

[scottpellegrin]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

Laddies,

Step 1-4 complete...still no spark.

Step 5 blue to blue/white I get nothing...no ohms and no tone on the meter. Red to red/white I get 141 ohms.

This mean the stator is the problem?

Thanks,

 

[Laddies]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

Yes

 

[scottpellegrin]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

So...my old man hauls this bad stator up to the marina looking for a used one. Dude there decides to test it and says the blue side has 1800 ohms resistance. I have a $500 Fluke meter and I got no ohms and no tone when I checked it. What's the deal? I tested while it was installed and again when I had it off. Dude also gets ohms from red side to blue side. Any thoughts???

 

[Laddies]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

I suppose that a broken winging or bad solder joint could cause that but I have never OHM tested one we always use the DVA test, as the OHM test can be kind of iffy

 

[scottpellegrin]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

What do I need and how do I do a DVA test?

 

[hotrod53]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

You said no "tone".... that may be your problem. Most DMMs are designed to tone at 200 ohms or less. If you're trying to measure higher resistance than that (such as 1800 ohms), you need to be on another scale and not listening for a tone, but looking for a number. The tone is for testing continuity only, and not to be used for actual resistance readings.

 

[Laddies]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

Your fluke meter may have a direct voltage reading position built into it depends on the model, so check the scales, if not you will have to buy a adapter (DVA) or you can build one like this, parts from radio shack are less than $10

 

[scottpellegrin]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

While cranking the motor I get 31.6 volts AC on the red side and 4.4 volts AC on the blue side. Are these numbers indicating a good or bad stator?

 

[Laddies]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

Bad if you built a DVA

 

[scottpellegrin]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

What should the numbers be?

 

[Laddies]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

180+ 25+

 

[scottpellegrin]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

With DVA I purchased I get 11.7 volts DC on the blue side. 41.0 volts DC on the red side.

 

[Laddies]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

It's bad

 

[scottpellegrin]

Re: No Spark - Mercury 50hp 4cyl serial # A133985

Curious what the numbers should be?