Engine Electrical Problem so been told

[brooksville_rebel]

I really need some help/advice/direction here if possible.Kinda long as I try to give all the info and details.
I bought a 1987 Mercury 3 cylinder 70hp engine off Craigslist back in Dec/Jan. I can't recall. When I went to get it It I made sure it started. So I bought it after asking and looking it over. I had it put on and the controls hooked up. I got it started and let it run for like 30 mins on the hose when it finally was brought back to me. ( I had bartered the engine install for the old blown engine.) I let it idle, did some high rpms for a few mins, not long, reverse etc. It bogged down at times, then would pick back up on its own. I changed out the plugs. Tested compression and they were all good. And took of the plug boots and watched for spark and the spark from each plug was good.
After that a week or so later I went out to fire her up and could not get it to start up. It cough and spurt but turn over again. The gas I had was somewhat old and I think the guy who hung the motor added more gas and got the feeling it was old gas. I had added additives, (probably too many times), K1000/marvel mystery during its down time. fly wheel w(*** SIDE NOTE - I drained out the gas which is premixed at 50:1 and used it in my lawn mower and it stopped starting up too after a few times running it also.***) Finally not able to get it started again I had the carbs pulled. I bought rebuild kits and my wifes son was suppose to rebuild them but only cleaned them. (Yes hes capable of the task and has done many rebuilds of auto/boat carbs ) Well that didn't do anything, but come to find out he only cleaned them, not rebuild them. So pissed I had a Mechanic come out and he pulled and took the carbs and sonic cleaned them and rebuilt them.
He came back and installed and they went to fire it up. It fired up after a couple of turns but would die again after a few seconds. Then on the 4th or 5th time there was a big ass backfire. They pulled the top plug wire and stuck some diagnostic plug wire in there with what looked like maybe a light and tried firing her again. Then said getting no spark or low spark, can't recall . They went through it and after some time that they think the engine has been tinkered with and has some engine parts that it shouldn't have on it. ( Said it has probably been Frankenstein'd. *** argh sigh ***)
- One was that the voltage regulator was missing off the engine. Showed me the place it was suppose to be mounted.
- Two was that there was a short between the two yellow wires coming out of the stator or trigger (I can't recall exactly what he said there) . He did a continuity test and it beeped out. (Tho I have no clue if its suppose to or not).
- Three was that they are assuming that whoever did the tinkering took the pulse wire and just hooked it to the first contacts that gave them spark. I think he said the purple wire.
- Four was that there was a rectifier put on the engine that didn't belong there and that's why it was tie-wired to the engine.
Now after they left to go find parts I called a Marina to see if I could find one so that it could be installed and get this running and gave them the engine info and serial number. They mech called me back and told be that that my engine didn't have a voltage regulator and used a rectifier. **sigh***
When they came back I mentioned that to them and they said it was possible but that this engine did require it. And w/o it could fry/drain the batteries and possible burn up the assemblies under the flywheel.
Then the other mechanic said something about the color of the flywheel. He said that this model should have a black or red one. Black I believe he said was a voltage regulator and redas for a rectifier one (I might have colors backwards if it really is true). That the beige one (on my engine) was off a Force engine.
I have searched the net, talked to couple different mechanics and get different opinions & different theories. Being most have a bias for a bank account deposit I am not sure were to turn to either fix it, sell it and get another or sell the boat and all which I'd rather not to cuz we love being on the water with the kids and grandkids.
I have attached some pics of the side of the engine. One I annoted with what they said and I can recall.
I really could use some help on troubleshooting this and getting some unbiased info on what could be wrong.
Thanks for taking a day out of your life to read all this and hope it made some sense.
Sincerely
Mark

 

[brooksville_rebel]

This is a link to a zip file of all the images I took of the engine wiring. Wouldn't let me upload most of them cause of their sizes.
http://thedewars.net/tmp/boatengine/boatenginewiring.zip
Its about 8 megs big. The names are what they are of in the engine or location in the engine.
Thanks
Mark

 

[gm280]

Okay brooksville_rebel, I read all the post and even unzipped the file and looked at the pictures.

My opinion is for you to buy the factory specific shop manual for your particulate engine. Don't buy an after market version, but the exact factory, year, HP, model, serial number shop manual for your engine. Because that manual will show you everything you could ever want to know about your engine. There would be no double talk from anybody about what is and isn't supposed to be on your engine.

I don't see a huge issue with your engine from just looking at the posted pictures. But I am not there and taking any readings and measurement myself either. It looks basically sound and really not hacked up and rewired. But I would have to be there and see everything for my self too. I would get that shop manual and start reading about your engine, and then make opinions about what could be wrong if anything. Obviously carbs, fuel pump, fuel lines and such things should be cleaned and repaired. But fuel tank and hoses from the tank need to be good as well. You need to test the spark. They sell spark testers very cheap (about $10 dollars at most auto parts stores) that will certainly allow you to see if you have an ignition issue quickly.

This is what such a spark tester looks like and are available everywhere. Once you have the spark, fuel issues known and good, then you can see if the engine will crank and run. And then you can adjust carbs and such for a quality run. JMHO

 

[brooksville_rebel]

Thanks gm280.!!! I will run up and get the tester and see about ordering that manual. . I truly and greatly appreciate you taking the time to go through all that and helping out. !!!
I have been reading what I believe is the manual from the boat library I think its called. Slowly getting a tiny tiny grasp of a few things.

I found what I believe to be the ACTUAL rectifier on the block. The one the mechanic said was it is not it. Its a Ignition adapter that goes with the stator. I have attached a pic of it. From the yellow wire on the left it looks like its melted around there.
If I have comprehended my readings right the rectifier is only there to help charge the battery. Is that right ? And should not keep the engine from turning over ?
I now am pretty certain that my engine is the 9 amp version and has no Voltage regulator on it like he thinks it should, just the rectifier (part number 62531A1)

I have removed the tank completely from the boat and cleaned it out. I went and got non ethanol gas and using a one gallon can to test with till she gets running again. I removed the fuel filter that was in the cowling and the one on the old fuel line and got a new fuel water separator. Crap I might need to change that out as I think I had the old gas going through it.

Again I appreciate the help and advice.
Mark

 

[gm280]

If your engine does have a 9 amp stator setup, yes that is for charging the battery and has no bearing on the engine starting or not. And if you have a 9 amp stator, then you have to have a rectifier as well. You can't charge a battery with AC voltage and the rectifier converts that AC stator voltage to DC for the battery to charge, So that should be a seperate circuit and not a cranking and running issue. Once you do get the shop manual you will be able to verify everything about your engine and learn so much as well. And that is the proper way to do things. Learn as you go and fix things from the knowledge you gained. Of course members on here are always wiling to help with issues as well. JMHO

 

[brooksville_rebel]

Okay been looking for the service manual. Searching found this site http://outboardmanuals.com. I assume its the
[FONT=&quot]90-86135--5 /1-593 manual but the SN don't seem to match up 228735 is mine and its not covered.[/FONT]

 

[muc]

Can you recheck the serial number. It appears to be missing some letters?

 

[brooksville_rebel]

0B228735
Thanks
Mark

 

[brooksville_rebel]

Got a spark plug tester like the one above. Wife was at work so had my 7yr old son watch the light since he wasn't able to turn the key.
He said each plug lite up. Orange and white light and blinked on and off. So I assume that has to be something on the good side, or at least hope it is.

 

[muc]

service manual 90-13645 2 70/75/80/90 3 CYL (1987 - 1993) & 100/115 4 CYL (1988 - 1993)
looks like your engine has had the "red stator" update. The part that is tie strapped is an adapter and is part of the kit. see parts bulletin POB-96-01 for more info.
Not sure about a "Orange and white light and blinked on and off" but to test for spark you need a spark gap tester with the gap set to the spec that is listed in the service manual --- want to see a nice blue spark.
You do need to replace the burnt rectifier and the end of the wire. While that part isn't needed to start the motor, if the motor is run too long with it bad the switch box can go bad.
Your next step is to do a compression test and/or a leakdown test. Also a proper ignition total output test.(spark gap)

 

[brooksville_rebel]

Thanks Muc,
The orange/white blinking is how my son described the tester when I did it. I will have to wait till the wife is available to turn the key. I assume the blinking is the plug firing. The tester I got doesn't have the ability to set the gap guess it only shows it firing.
As for the switch box is that the box in the upper left corner of the engine in my pic attached in the first post ? And is that also know as the "power pack ?".
We did a compression test when first got the engine and came out good.
No clue what a leakdown test is ? I'm a computer/network guy, mechanics is over my head , sadly. Will have to go search that out.
In the pic in the top post I attached the mechanic unplugged the two yellow wires coming from underneath the flywheel and did a continuity test. IT beeped out and said it shouldn't have. Is that right ? and does it mean anything or show a problem ?
Thanks guys for all the help and insight, learning stuff slowly as I research all this.

Mark

 

[DeepBlue2010]

Compression testing can only tell you that there is a leak in your cylinder but it can't answer the questions where is the leak coming from. Is it from the lower end of the engine (leak through the rings) or from the top end of the engine (leak through the valves or the head gasket. Leakdown test can answer these questions and help you determine where is the leak coming from. There are good youtube videos on the leakdown test but unfortunately some of them forgot to say that you MUST bring every cylinder you are testing to Top Dead Center (TDC) compression stroke before you start the test

 

[brooksville_rebel]

DeepBlue
Thanks. I will go and watch and learn.

 

[muc]

Without an adjustable gap a spark tester doesn't stress the ignition system enough to give valid results.
Yes, the component in the upper left is the switch box. Mercury calls it a switch box and Johnson/Evinrude calls it a powerpack.
When you say the compression test was "good" do you know what's the numbers were?
A leak down test is a better check on a 2 stroke. I have seen engines that passed a compression test but fail the leak down
The 2 yellow wires go to the stator. They need to ohms tested. There should be continuity between these wires but not to ground on either one of them. A continuity tester isn't the right tool for that test, it requires a volt ohm meter.
All of these testes are covered in the service manual. At this point it seems to me that your mechanic might be over his head. It might be best to learn about this yourself or find a Mercury Marine Certified Technition. Things can get expensive pretty quick.

 

[Fed]

Get an open air adjustable tester.
You can crank it yourself by turning on the ignition switch then jumping a wire from the large main +Positive terminal on the solenoid to the small +Positive terminal.
(Not the small one that goes to ground)
You can also get remote starter switches to do the same job.

If it fails the test then disconnect the yellow wires & try again.

Although the charging system (yellow wires) is separate from the ignition circuit the CDI website advise disconnecting the rectifier from the circuit.

Rectifier/Regulators can cause problems ranging from a high-speed miss to a total shutdown. An easy check is to
disconnect the stator leads to the rectifier (Make sure to insulate them) and retest. If the problem is gone ? replace the
rectifier/regulator.

Download the trouble shooting manual from the CDI website, I think your motor would start on page 80.

 

[brooksville_rebel]

Without an adjustable gap a spark tester doesn't stress the ignition system enough to give valid results.

Yes, the component in the upper left is the switch box. Mercury calls it a switch box and Johnson/Evinrude calls it a powerpack.

*** Okay just confusing reading some forums threads and some call it the power pack and others switch box, and the service manual refers to it as the switch box so wanted to make sure that what I have been reading and looking at was what I thought it was.

When you say the compression test was "good" do you know what's the numbers were?

*** Yea I had rented the compression tester from auto zone. I can't recall the numbers but two were even and bottom was within a couple, less than the 10% I have read they should be on the forums.

A leak down test is a better check on a 2 stroke. I have seen engines that passed a compression test but fail the leak down

** I searched it and will need to study up on it more. I saw 3 tests for the leakdown so need to read up on them and how to do them.

The 2 yellow wires go to the stator. They need to ohms tested. There should be continuity between these wires but not to ground on either one of them. A continuity tester isn't the right tool for that test, it requires a volt ohm meter.

*** Yea I thought there was something funny about that. I thought it should beep. He didn't try to ground. just unplugged the yellows from their other end and stuck the probes in the sides that went back up to the stator. Seemed off to me but again I am pretty stupid on this stuff.

All of these testes are covered in the service manual. At this point it seems to me that your mechanic might be over his head. It might be best to learn about this yourself or find a Mercury Marine Certified Technition. Things can get expensive pretty quick

*** Sad part is that he has Mercury certification. Hell has a few certs. He did say he doesn't or hasn't really messed with engines this old. But still...

I am trying to learn, that's why I'm here and posting and reading. I d/l the service manual and going through it slowly. I will need to get the hard copy or print it out. Kinda hard to follow reading it on the computer than going out and trying to remember what I read. No memory cells left at times.


Thanks for all the help and advice. I greatly appreciate it , tho at times it probably should be dumbed down for me
Thanks
Mark

 

[brooksville_rebel]

Get an open air adjustable tester.
You can crank it yourself by turning on the ignition switch then jumping a wire from the large main +Positive terminal on the solenoid to the small +Positive terminal.
(Not the small one that goes to ground)
You can also get remote starter switches to do the same job.

If it fails the test then disconnect the yellow wires & try again.

Although the charging system (yellow wires) is separate from the ignition circuit the CDI website advise disconnecting the rectifier from the circuit.


Download the trouble shooting manual from the CDI website, I think your motor would start on page 80.

Thanks d/l it few mintues ago.
This is what your talking about for a open air one ?https://www.amazon.com/AMPRO-T71240-Energy-Ignition-Tester/dp/B00A8FO87S or this one
https://www.amazon.com/gp/product/B0...=ATVPDKIKX0DER

 

[Fed]

The first one because it's adjustable.