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87 Mercruiser 50 No Spark

caseman

New member
"Left something on killed batt

"Left something on killed battery, then to make matters worse used another battery to start boat then tried to switch batteries while boat ran. I got an arc, boat shut down. No Spark. Change two fuses under dash that blew, and changed Ignition module, and I have fuel. My son is going in the Navy soon panning a trip so any help would be greatly appreciated."
 
"Thomas

So who's a naug


"Thomas

So who's a naughty boy then, swapping batteries mid stream like that is a definite "No No".
I assume your engine is a carburettor type and not EFI, if it is an EFI engine your computer is now toast

Check your alternator/regulator, either or both are probably fried as well.

Cheers
Peter C

Hey guys I have been missing in action for a while, does anybody want to start a debate about the differences between automotive verses marine engines again.
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Just Kidding
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"
 
"THOMAS:

What engine and ye


"THOMAS:

What engine and year? Did the main engine breaker trip? Push the large RED button in hard.
Now explain what the engine WILL do.

Peter:

Aren't you rebuilding two inline 6 cyl. truck engines for your tug? Please tell us all about how you plan to marinize them.
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"
 
"Guy.

"TUG" Why are


"Guy.

"TUG" Why are people so unkind, its my weekend office, now get it right.

Actually Guy the short blocks I have to rebuild are genuine mercruiser engines but the ones in my boat currently are GM truck.

My engines are currently raw water cooled and so the only marinizing they have is the stainless gaskets, brass welch (freeze)plugs and pencil anodes in the water jackets.

Plus the normal marine externals.

When my new engines are ready to go I am probably going to convert them to fresh water cooled but that is still a bit up in the air as I am also considering selling her next season and looking over in your part of the world for a replacement to ship back over here as deck cargo.

Weather has been crap over here at present so there hasnt been much boating and my TUG as you so called it is due to have its backside wiped so its nearly time to park it next to my workshop for a few months again.

Cheers
The Boy From Oz"
 
""...engines but the ones

""...engines but the ones in my boat currently are GM truck." What about the cams?

Did you just throw a live grenade into the "engine war pit"?
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Cheers and beers, Guy"
 
"Someone also said where you a

"Someone also said where you attach the wires to the distributor is a module or something that probably fried??? I tried to take it out, but how do you get the cap and the plate underneath off?

It will turn over, spark to coil but that is it."
 
"Guy.

Yes to the grenade, I


"Guy.

Yes to the grenade, I just couldnt resist after reading a previous long drawn out posting about the differences .
I am unsure of the cam grinds, it depends on how lazy the guy was that fitted the engines originaly, you can be assured the new ones will be suitably ground for the job at hand.

Now back to you Thomas

Thomas can you just give us a bit more info if you can on your engine and ignition system, is it a carburetta engine ? is the ignition system standard ? are you getting a voltage reading to the + side of the coil with the ignition on ?

When you spike a system like you have you can do a small amount of damage or heaps depending on your individual electrical system, you say you have "spark to coil but that is it". can you elaborate on that a bit, are you saying that you are getting a spark out of the coil tower when you wind the engine over ? Is the tacho behaving normaly when you wind over the engine ?

If you go back down through the postings list you will find one about the "backdoor being open again", click on the links provided by Bondo and you will be able to download a manual to suit your engine, you will be able to trouble shoot your system using that manual, the test procedures are well explained and easy to follow all you need is a good quality multi meter.

A good manual is a must for the budding boat owner}

But give us some more info and we will see what we can suggest for you, it can be a very expensive repair if you just keep replacing parts without trouble shooting first.

Regards

Peter C"
 
"If you are getting a GOOD spa

"If you are getting a GOOD spark then the module is ok. Try a new set of plugs, replace the cap & rotor if corroded and see if there is spark to the plug ends of the wires. Changed fuel filters? This work is all basic preventive maint. Clean the flame arrestor (top of carb)? Choke working? Change plug wires if needed."
 
"did a number of tests today.

"did a number of tests today. 12 V at battery. With switch on 9.7 V to coil. Red white wire disconnected from distributor with power on 9.7V. I took a spark tester hooked it up to wire coming out of coil, attach to ground.took green white wire off dist. powered it up, both green/white to same ground ( at different times) no spark. This test was a suggestion online. Why 9.7 V?"
 
Thomas
Your wiring to the po


Thomas
Your wiring to the positive side of the coil is through a resistor.
Sometimes this resistor is external (rather in the wiring harness or bolted externaly to the coil) and sometimes internal in the coil.
9.7 is fine.

Cheers
Peter C
 
"OK here is where I stand. 12V

"OK here is where I stand. 12V at battery, 9.7 V at coil, red/white wire to distributor from ignition module 9.7V. Bought used ignition module ( engine threw a rod) also purchased new rotor and distributor module. Still no spark.
With power on, spark tester attached, green /white from module to ground,no spark."
 
"-----------------------------

"--------------------------------------------------------------------------------
more tests. put + tester lead to power and - lead to distributor, dist. is grounded. took grey tach wire off coil, to see if tach was shorted out, still no spark. Wah"
 
"Thomas

I am inclined to ag


"Thomas

I am inclined to agree with Guy, it is well worth trying a coil but I am not big on Second hand electrical components so I am still a bit suspect of the module you have fitted.

Is the coil + voltage remaining constant around that 9.7v mark when you crank her over ?

Cheers
Peter C"
 
Let me try the coil. The mecha

Let me try the coil. The mechanic told me the boat source boat for the part threw a rod so it sounds like it might be good but???? Stay tuned will try new coil tomorrow AM.
 
"Try this procedure.

Tests


"Try this procedure.

Tests for Thunderbolt Ignition:
W/ignition key on AND BILGE WELL VENTILATED OF GAS FUMES!!!

#1 - Connect your voltmeter neg. lead to the engine ground and pos. lead to the white/red wire terminal at the dist. It should read 12 volts.

#2 - If 12 volts is present, remove the coil spark wire from the distributor and connect it to a spark gap tester to ground. Remove the white/green lead from the dist. terminal. Turn the ign. key to on and strike the white/green lead to ground. If there is spark, replace the ignition sensor in the dist.

#3 - If there is no spark, substitute a new coil and repeat test #2. Now if you get spark, install a new coil. NO SPARK, replace ign. amp.

#4 - In #2, if there is No voltage present, disconnect the white/red wire and check it again for 12 volts. If 12 volts is present, replace the ignition sensor inside the dist. cap. If no 12 volts present w/it disconnected--ignition amplifier is shot and must be replaced."
 
"WE HAVE SPARK. Still a wonder

"WE HAVE SPARK. Still a wondering what was wrong. Put a new coil on today, no spark. Put a new ground for distributor. put on old ignition module, took some sand paper to get some bare metal for ignition module ground. And low and behold it fired right up. I'm going to switch out that ignition module again to see if it is good, sell it on Ebay. I hope I wasn't sold a dud. It is running smooth. I want to thank all of you very much for your help. I could not have done it without you. My son left tonight for the Navy we didn't get to take our trip together, but I'm sure we will some day."
 
"Thomas

Thats good news, s


"Thomas

Thats good news, sorry you didnt get to go for a run with your boy but I am sure there will be plenty of more times ahead, if nothing else you have learned a bit about your engine that you didnt know before.

Cheers from Oz

Peter C"
 
Thomas

You have good tastes


Thomas

You have good tastes.
Casey lives about 45 minutes from here and i was told that her and some of her other country artist friends regularly have an un advertised Jam sesion at one of the local watering holes.

I keep promising myself I will go there one night but havent found the time yet.

Cheers
Peter C
 
"I have met Kasey and her fath

"I have met Kasey and her father Bill several times.They couldn't have been any nicer to my family and I, If all Australians are that friendly, it must be a great place to live. Thanks again for all the help."
 
Thomas.

I am completely bia


Thomas.

I am completely bias when I say it is the greatest place in the world to live and I would like to think that the vast majority of Ozy's are as friendly as the Chambers family were to you and yours.

There is always a cold beer in the fridge and fuel in the boat if you are ever in the land of Oz just look me up.

Cheers
Peter C
 
It is my hope to one day get t

It is my hope to one day get to OZ. It is just the flight that is a killer. Just saw a singer named Audery Auld she was from Tazmania. A long way from here.
 
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