1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, coils?

[fallautumn2]

Hi guys,

HELP PLEASE!!!!!!!!

per my earlier post, I ended taking the engine to an authorised Mercury dealer to replace both the stator and trigger after they diagnosed these as being faulty - That cost me $978.

I just got a call this morning and was told that new stator and trigger installed but no power at all was coming out of the switchbox - thus this needs to be replaced and they also said that the coils may need to be replaced as well. I asked if they could bench test the switchbox and coils to tell if they were faulty. they said that mercury don't provide any bench testing equipment to be able to check these components - you have to work from the stator and trigger down replacing any faulty components as you go.

I was very surprised to find that the largest marine engine manufacturer in the world couldn't bench test individual electrical components to determine if they were serviceable or not??

From your experiences is what they told me correct?? I have now been quoted $378 for a new switchbox and advised that the coils would probably need to be changed as well @ $78 each thus another $312. In total another $690 without labour cost.

Just as a recap of the engines recent problems it had developed a crippling problem. When you pushed the throttle down to try and get full speed you only got maybe 1/2 throttle (ie 1/2 speed). If you leave the throttle on full it will, after maybe 10 minutes or more, suddenly surge forward to its correct full speed. I rebuilt the carbs and fuel pump to no avail.

I don't understand how I was getting electrical current to the bottom 2 coils (bottom 2 cyclinders were firing) at least prior to replacing the stator and trigger and now the switch box is completely dead!!!!

HELP please !!!!!!!!!!!!!!!!

 

[futech]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

If you have faulty coils its best to just change the lot. New coil vs old coil won't be as good on fire. The coils should be tested on engine both ohms and then voltage while running. They would have the equipment for it. If you have had a faulty stator and trigger i would say that yes your switchbox would be shot to.
Im in the automotive trade and its the same really. People don't change spark plugs, so puts a lot of strain on coils. If its a COP system then its just coils, if its standard with external ignitor that usually goes also. Then they complain that the coils cost so much yet they could have avoided it by replacing plugs which are cheap as hell.
At the end of the day mate, anything electrical or electronic won't last, it doesn't matter what your dealing with. The prices you have been quoted seem pretty reasonable. I myself have just spent nearly 2k on parts and still have a problem with my system.
You don't want to break down on the water.

 

[Faztbullet]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

Merc coils rarely go bad, on a rating scale of 1-10 on having bad coils .......a two.

 

[CharlieB]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

Call the dealer and tell them you are coming to pick up your boat and also want the old parts ready for you to pick up.

Some 'techs' fail to follow proper diagnostic proceedure and end up swaping out parts until they finally replace the whole ignition, while you pay for it all.

We don't play that game here on iBoats.

we teach you how to properly test so you can make a fact based decision as to what part is failing.

Once you have your boat at home you will need a properly charged battery, clean battery connections at both ends of both cables AND the starter cable. A remote starter button is handy but not absolutely necessary, a DVA meter or a DVA adaptor to use with any volt/Ohm meter, and an adjustable gap spark tester.

Download and save a copy of the CDI Ignition guide, FREE, it is a compilation of sections of factory service manuals detailing testing and troubleshooting ignitions and covers most every common ignition out there.

Following CDI's directions you can test the stator, the triggers, switchbox, and coils, and determine exactly which parts is at fault.

We have done this literally thousands of times, ask us anything and we will help you understand what and why, so you can fix your boat motor without the part price gouging that has happened to you so far.

 

[CharlieB]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

I forgot the CDI link

ISSUU - CDI Electronics Practical Outboard Ignition Troubleshooting by CDI Electronics

 

[fallautumn2]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

Hi Charlie B,

I just got back to the post as I've been working some overtime. Thanks you for your very generous assistance and information. Its reassuring to see that my presumption that the merc service technicians should have been able to test individual components was correct.
Re the DVA meter, I have a digital multimeter which an old friend gave me before he passed away some time ago - being honest I have no idea how to use it. Also I have looked online for the DVA adaptor and cant find any in Australia (I live in Sydney). The only ones I have found were in the States and don't appear to be able to be shipped outside of the US.
I do have a Seloc manual and have noticed that they give OHM scale readings which I think are values I would need to get on a normal multimeter set on the OHM's scale. Is this correct, and if so could I perform the tests with these values and the non DVA multimeter that I have??
Also, when I am running these tests (eg stator, trigger, switch box and coils) do I need to crank the motor to send the right level of current through the various electrical components installed on the engine, or do I just test with the ignition switch on or even off????
Also I have the old stator and trigger which they replaced how would I test these (which are obviously not now connected to the engine??
I know that these questions must seem very basic and perhaps foolish but I freely admit that I am no electrical genious or even novice. Thanks in advance for your help - again it is greatly appreciated.

Kind regards, Kevin

 

[sam am I]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

DIY DVA.....If ya end up needing one





1N4007 1A 1000V Diode - Pk.4 - Jaycar Electronics

47uF 450V RB Electrolytic Capacitor - 105oC - Jaycar Electronics no luck on 22uf but it's a moot point, 47uf will work just fine for this app.

http://www.jaycar.com.au/productView.asp?ID=RR2846&form=CAT2&SUBCATID=968#1

I'm not sure what a Jaycar is but the all knowing oracle known as Google said your Radio Shacks have this Jaycar affiliate and could get these types parts in Au.

BTW, I don't know Bill but, he must be an upstanding gentleman and a true scholar because he uses engineering graphing paper!!

 

[racerone]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

Hurry, take big steps in rapid succession and find another shop.---All these " faulty " electrical parts points to poor diagnostic skills !!!---Last one of those I worked had the exhaust 2/3 plugged with carbon and bad lower seals on crankshaft.---------Dealer had replaced electrical parts for some reason.

 

[CharlieB]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

Ohm's test are resistance tests done on a static, non-moving part. Any voltage and you will smoke the Ohm meter.

DVA are cranking tests of voltage generation WITH a small load on the part causing it to do work. A simple voltage test without any load can falsy read voltage yet still fail completely once a load is connected, the windings on the charge coil must generate current, the winding seperates and fails, no voltage under load, but passes both the ohms and simple voltage tests.

The DVA adaptor MUST be used to positively test and prove the part.

The black wire with the thin yellow line on the switchbox that connects to the engine wiring harness is the 'ground-to-kill' wire, a ground fault in the ignition switch, lanyard, or wiring harness will kill spark. You can replace the entire ignition system and still have no spark.

Disconnect this wire at the engine harness then retest for spark.

 

[fallautumn2]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

Ohm's test are resistance tests done on a static, non-moving part. Any voltage and you will smoke the Ohm meter.

DVA are cranking tests of voltage generation WITH a small load on the part causing it to do work. A simple voltage test without any load can falsy read voltage yet still fail completely once a load is connected, the windings on the charge coil must generate current, the winding seperates and fails, no voltage under load, but passes both the ohms and simple voltage tests.

The DVA adaptor MUST be used to positively test and prove the part.

The black wire with the thin yellow line on the switchbox that connects to the engine wiring harness is the 'ground-to-kill' wire, a ground fault in the ignition switch, lanyard, or wiring harness will kill spark. You can replace the entire ignition system and still have no spark.

Disconnect this wire at the engine harness then retest for spark.

Hi again Charlie,

thanks for clearing up the DVA vs normal multimeter. I did another search using "peak AC voltage meter" as my search parameter and I got 1 hit. Could you please look at the specs that follow and tell me if this is in fact a DVA meter. The following one is available in Australia.

Also can I use the normal multimeter to check the now removed stator and trigger using the Ohms scale and the Seloc ohms values.

Thanks again, Kevin
True RMS CAT IV Digital Multimeter - IP67 Rated


• True RMS
• Auto power-off
• Backlight
• Data hold
• IP67 rated
• Diode test
• Autoranging
• Temperature
• Audible continuity
• 10 A Current range
• Relative measurement
• Double molded case

Specifications
Display: 40,000 count
Category: Cat IV 600V
Basic accuracy: 1%
DC voltage: 1,000V
AC voltage: 1,000V
DC current: 10A
AC current: 10A
Resistance: 40Mohms
Capacitance: 40µF
Frequency: 100MHz
Ave/RMS: RMS
Duty cycle: .1 to 99.9%
Temperature: -50 to 1000?C
Dimensions: 187H) x 81(W) x 50(D)mm

This rugged meter is designed for professional use and will provide many years of reliable service. It measures up to 1,000 volts AC & DC and is rated to CAT IV 600. The meter includes temperature and capacitance ranges, as well as peak-hold and min/max options. It is water and dust-proof (IP67) and features a double molded case that will easily withstand a 2m fall. Includes K-type thermocouple.

 

[Faztbullet]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

No one makes a digital DVA meter you must build or buy a DVA adapter. The only meter with built in DVA is the ESI analog distributed by various dealer and is the supplier for Merc.. Below is link for you to seach..
Amazon.com: dva meter

 

[fallautumn2]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

No one makes a digital DVA meter you must build or buy a DVA adapter. The only meter with built in DVA is the ESI analog distributed by various dealer and is the supplier for Merc.. Below is link for you to seach..
Amazon.com: dva meter

Thanks Faztbullet, I went to the Amazon site, per your link, and a customers review indicated that he had ordered 2 units from Amazon and both were defective, and there was non existent warranty support from ESI, plus a time delay of 4 weeks. It looks like I'm going to have to try to build one as per Sam I am's above post. I am not very confident with electronics so I hope I don't stuff up the build.

Thanks again.

 

[sam am I]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

Thanks Faztbullet, I went to the Amazon site, per your link, and a customers review indicated that he had ordered 2 units from Amazon and both were defective, and there was non existent warranty support from ESI, plus a time delay of 4 weeks. It looks like I'm going to have to try to build one as per Sam I am's above post. I am not very confident with electronics so I hope I don't stuff up the build.

Thanks again.

Hold the phone.............Use a/the "Peak hold"(Min/Max, read your meters manual) if you have it.......same diff. That DIY circuit(as shown) does no more than charge up the capacitor to the positive peak minus the forward diode drop of approx .6/.7 volts of the AC(any positive going voltage actually, AC/DC or Bon Scott's High Voltage) coming into it. In fact, that DIY DVA circuit is considered a "peak detector"(among other things) in many nerd circles around the world, they've been used for 1000's of yrs +/- 2 in TV's/Radio's, for auto gain circuits, instrumentation, sample and holds, ADC's and radio controlled caveman clubs.

The resistor(1 Meg) is merely there to ensure dis-charge of the capacitor at a certain rate so as to keep "updating" to dynamics (things change in time ya know) for the circuit/meter reading the DC potential that is being developed on the capacitor. Our Fluke DMM's etc with/on "peak hold, Min/Max" do the same thing exactly cept digitally "update" and store and average all the values for us automagically. One of mine, think it is the 77, even beeps every update(errrr, might be auto hold). At any rate, you're good to go given those features you listed i.e., the peak hold and Min/Max(diff is response times, read the book).

A "good", plenty fast enough meter's peak hold response time should be in the 250uS ball park which is the minimum length of time an input must stay at a new value to be recorded accurately, or 1/250uS = 4000 Hz aka 4000 CPS(cycles per sec), which is 240,000 CPM(cycles per minutes) which obviously, can be equated to being able to measure things(signals/pulses, thumps and bumps in the night) in and around an engine that have this cyclic rate of 240,000 P/M (pulses per minute) or slower. So for example, if measuring a 12 pole stator's output signal that gives 6 P/R(pulse per rev) and at 10,000 R/M(RPM) = 60,000 P/M(pulses per minute)....so buy the True RMS CAT IV Digital Multimeter, just check/re-check those response spec's, don't sweat the/any DVA functions/meters and peak hold away.

http://www.youtube.com/watch?v=Z_WRENMIwA8

lil reading tonight for ya.

http://www.allaboutcircuits.com/vol_3/chpt_3/5.html

(Nevermind the series 1KΩ, the teacher put that in there just to justify their paycheck.......J/K, it always exists though and is important but not here, it's just lots smaller for us here, 0.5Ω'ish on a stator winding wound for batt charging for example. Note the voltage on their capacitor charged up but, never dis-charges. They have no 1 Meg resistor on their circuit, so the capacitor(in a perfect world) would never dis-charge, thus, never allowing new LOWER valves to be measured. That's as complicated as the infamous "DVA" circuit is)

http://en.wikipedia.org/wiki/Envelope_detector

Yes, this same exact circuit is the bases on how AM/FM radio's work too! Funny that.


This should get ya going and yes, you can build the DIY, save some money, burn something perhaps, learn about installing diodes backwards, negative voltages, polarize capacitors get hot, explode sometimes when charged backwards and contain lots of smelly smoke and lots of fun paper inside aaaaaaaand, use with your old meter(on DC setting) all with good results too!! Just messing with ya, it would work fine, ask if you need help, it's pretty simple and safe

 

[bruceb58]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

DVA.png Photo by mikeyb3649 | Photobucket
Home Made Peak Voltage Adapter - YouTube

The sample rate of most meters is just way too slow. Assuming your meter is going to sample at the exact peak if the sample rate is similar to the frequency of the pulses is like finding a needle in a haystack.

 

[CharlieB]

Re: 1987 Classic 50 - HELP PLEASE electrical problems - Stator, trigger switchbox, co

LOAD is necessary , voltage alone is merely potential. Without any load there is no real current and the circuit is not doing any work. Even though the resister value is very low, it is sufficient to induce a current.

Another method I used before buying my DVA meter in the late 80's is to connect a voltage source to one end of the circuit and a test light to the other end, connect the test light to the voltage source and watch for a light indicating the circuit carries. Many times the light would fail proving the circuit bad yet a volt meter would still register once the test light was disconnected, proving a broken yet abutted winding, it would carry potential voltage yet fail with any load. NOTE: If testing a circuit only use a voltage source less than or equal to the voltage the circuit normally operates. Do NOT over-charge the circuit, you will cause damage.

I'm just a mechanic, what do I know.