Mercury ignition parts - uk

[thestig1973]

I'm pretty sure that the red stator is faulty on my mercury 15hp 2 stroke

The engine was "new to me" and died after a couple of hours use on my first outing, but ran perfectly until then

I have a few other things to check before throwing cash at parts (magnets under flywheel)

Can anyone recommend a uk supplier or possibly anyone who can refurbish the ignition parts, so far my searching is finding parts in America

[Fenlander]

>>>I'm pretty sure that the red stator is faulty

Does it fail either of the resistance tests in 2A-9 of the manual...

Boatinfo - Mercury Service Manual for 6-8-9,9-10-15 hp

... when tested exactly per the book?

[thestig1973]

I'm going to test again tonight, but I ran through all the test procedures, all readings seemed slightly lower than expected but the red stator test showed no reading at all

[Fenlander]

OK... not doubting as such just trying to think it through. The red stator generates a voltage for the CDI unit (sometimes called the switch box) and this is for both cylinders... so if you can still get a spark from one coil something is odd about the test readings.

It's the trigger and CDI unit going faulty that can end up with just one coil being fed a signal to fire.

Resistance figures can be lower across the board when it's cold... I think the spec readings are at 20degC.

Check this out too... http://www.cdielectronics.com/wp-con...20-%202012.pdf

Around page 78 for your motor.

If you have double checked and there is still no reading for the stator is there anywhere you can see that the wires bend round something so that the copper core could have broken with the outer sheath looking intact? Give the wires a good flex while the resistance meter is on to see if you get a flicker.

If nothing obvious I guess you will have to pull the flywheel to get a better look.

[Fenlander]

Oh yes... did you just do the resistance tests on the stator?

At the bottom of page 2A-9 there is a voltage output spec for the stator and you should get somewhere near that with a brisk pull of the starter cord.

Is this your stator... I reckon it is if you have a red one (but see below)??

http://www.blackdogmarine.com/produc...oducts_id=1080

Blooming expensive!

Edit: Why do you think you have a red stator? According to Mercury this was a 1999/2000 year onwards improvement and if your 1995 outboard has it then it must have been fitted with a conversion kit at some time. Read here for an excellent explanation of the system & change...

http://www.crowleymarine.com/sb/2/4860

[thestig1973]

That's great info Fenlander

I'll read through it all in detail when I finish work and hopefully get closer to diagnoses

I've read up and just presumed mine had the red stator, so possibly incorrect

I completely removed switch box and checked all bullet connections, earths etc

Strong spark on either coil which leads me to believe output from switch box is only to one green (coil) wire

I understand this engine suffers from broken magnets under flywheel which would stop signal/voltage, unfortunately my tool box is looking a bit bare so I need a 22mm socket, wrench and flywheel puller to check anything more than voltage/resistance

[thestig1973]

Multimeter scale?

R x 1
R x 100 etc?

I'm getting expected readings if I mess around with the multimeter settings but tbh I'm not sure I'm using the scales correctly

[thestig1973]

Budget meter.... Is this up to the job?

[Fenlander]

Yep that's fine for these basic tests.

Take as an example if you did have the red stator and were testing as per page 2A-9 of the manual...

Between the green/white and white/green leads you are looking for a test result of 370-445 ohms so set you meter to the 2000ohms scale.

If you were testing the trigger coil between brown/yellow and brown white expecting 6.8-8.5 ohms use the 200ohms scale on your meter.

You just go for the lowest scale that you don't expect to exceed by a margin.... if that makes sense.

[thestig1973]

Originally Posted by Fenlander

Yep that's fine for these basic tests.

Take as an example if you did have the red stator and were testing as per page 2A-9 of the manual...

Between the green/white and white/green leads you are looking for a test result of 370-445 ohms so set you meter to the 2000ohms scale.

If you were testing the trigger coil between brown/yellow and brown white expecting 6.8-8.5 ohms use the 200ohms scale on your meter.

Thanks 👍I do appreciate your help

Testing black stator
Red lead to black/white
Black lead to ground

Seems fine

[thestig1973]

Red lead to black/yellow
Black to ground

Seems ok (presuming meter is on correct setting)

[Fenlander]

Edited... posts crossed!

You could be on the bottom 200 scale for that for a more accurate figure in the 32-38 region.

How about black/yellow to black white? Still on 200 scale. Looking for between 31-37.

BTW your 132 in the first test is perfect.

[thestig1973]

Red lead to black/yellow
Black lead to black/white

Slightly low reading

[thestig1973]

Trigger test

Red lead to brown/yellow

Black lead to brown/white

[Fenlander]

The reading in post #13 might be more accurate on the 200 scale?

So might the reading in post #14.

[thestig1973]

Ok, I'll try again tomorrow, as you can tell from the pics I'm loosing light now

Thanks for sharing your knowledge though, I will be a happy man if I can get this diagnosed and fixed, even if the part is expensive it's saving labour costs and much more satisfying to investigate the problem personally

[Fenlander]

No problem. Get those update readings tomorrow and we'll go from there.

[Fenlander]

Should mention if resistances check out OK the cranking speed voltage tests would be informative.

Sadly a budget meter will not correctly show the readings from electronic ign systems due to the very short voltage peaks. You either need a very expensive meter or a DVA/Peak voltage adaptor.

Here is the problem getting a steady reason shown on a quad...

https://www.youtube.com/watch?v=MmFOPjHqL7Q

Here is how to make the adaptor if you have a friend in electronics...

https://www.youtube.com/watch?v=TWsE2tPjHuo

[thestig1973]

Fantastic, thanks 😀

[Fenlander]

And my final bit of the night... a pretty good video of a guy working right through ign tests which might give some ideas...

https://www.youtube.com/watch?v=MDbv...N-0EoX7Skkh8AQ

Different outboard but same basic principles.