Merc 1000 not getting spark, checked everything I know need pointers

[Bigbearslayer]

Ok let first start off by saying that this boat belongs to my buddy but we have yet to take it out because of runablilty issues. He completely tore down and rebuilt all the carbs and fuel lines, it is all brand new now. He brought the boat over to my house and we messed around with it a little more. We got it to fire up and it was idling and running great. Then my buddy shifted it into drive and all was well, he then shifted to reverse and it shut down. We put the motor back into neutral and started the engine again and it was running good until he put it in reverse and it instantly shut down. Basically we might have a two part problem here because I think there might be an issue with reverse but the main issue right now is that there is no longer any spark.

So far I have pulled a plug and used it to check for spark on all of the spark plug wires while the engine is being cranked and there wasn't any spark on any cylinder.

Next I pulled the distributor apart and check the points for cleanliness and proper gap, all was well in that department. While I had the distributor apart I checked the condensers by taking a resistance reading from the lead of the condenser to the body of the condensor but the readings went from OL to a range of numbers on both condensers which leads me to believe that they are at fault. I understand this could be the result of the no spark condition but the next thing I checked makes me wonder if it might be something else and the weak condensers are just amplifying this problem.

While the engine is cranking I tested to see if there was any voltage going to the coils and there was nothing on either coil, is this normal.

Basically I am just looking for a little advice on where I should have voltage in regards to the ignition system and how much and also some proper techniques for testing the coils, condensers, points, and anything else that I may have overlooked.

Thanks in advance for any input.

~Eric

 

[Maxz695]

Re: Merc 1000 not getting spark, checked everything I know need pointers

I,ve only read part of this long story but to me it sounds like your having issues with the Shifter neutral starting switch. This switch only allows the engine to start in neutral. The switch may have come loose or the shifter has worn inside. This is only a suggestion that may hep you narrow down the problem. If you can disconnect the wiring harness from the engine and then test for spark. You may have to get a remote starter or jump the soleniod. You can remove all the plugs and rope pull to check for spark at that time Being there was spark engine ran fine and restarted again after being put in neutral leads me to believe the switch has shorted in the shifter and there would be no power from there on when the switch went out

 

[merc850]

Re: Merc 1000 not getting spark, checked everything I know need pointers


Here's a wiring diagram for point ignition Merc 1000's.
Your problem might be bad wiring, poorly grounded distributor (there's a ground strap that goes from the block to the dis.), bad ignition switch.
There should be at least 9v at the coil + terminal due to the drop of the ballast resistors but 12v when starting.
You could jump a positive wire to the coils and see if it will start.
Condensers have to be checked with a meter that reads in microfarads and it would be a good idea to replace them anyway.
If the motor stops suddenly when shifting into R it might be a LU problem, have you checked the gear lube?

 

[Bigbearslayer]

Re: Merc 1000 not getting spark, checked everything I know need pointers

View attachment 107513
Here's a wiring diagram for point ignition Merc 1000's.
Your problem might be bad wiring, poorly grounded distributor (there's a ground strap that goes from the block to the dis.), bad ignition switch.
There should be at least 9v at the coil + terminal due to the drop of the ballast resistors but 12v when starting.
You could jump a positive wire to the coils and see if it will start.
Condensers have to be checked with a meter that reads in microfarads and it would be a good idea to replace them anyway.
If the motor stops suddenly when shifting into R it might be a LU problem, have you checked the gear lube?

Well the ground strap on the distributor is missing so I am going to replace that tonight. And you say that there must be at least 12v at the coil when starting but would it hurt anything to just run a straight 12v jumper to just give it a go and see if I am getting spark. If I could do that atleast I would know that the condensers are good enough and I can start narrowing it down to the wiring between the ignition switch and the engine somewhere.

Thanks for the info.

And by the way is the Neutral safety switch located in the cabin near the throttle usually.

 

[Maxz695]

Re: Merc 1000 not getting spark, checked everything I know need pointers

it should be in the throttle

 

[Bigbearslayer]

Re: Merc 1000 not getting spark, checked everything I know need pointers

Ok, well I hooked a ground strap from the distributor to the block in hopes that I would see a beautiful blue spark but to no avail. So I guess I will try jumping a straight 12v to the coil in the morning unless someone says it will ruin the coils. Any thoughts?

 

[Bigbearslayer]

Re: Merc 1000 not getting spark, checked everything I know need pointers

Ok, so I got the old merc purring like a kitten. It was a mixture of dirty points, poor wiring from the points to the coils, and like 4 bad connections in the wiring harness inside the boat itself. I guess that is why it is super important to use good butt connectors and really good wiring pliers when crimping those babies. As far as reverse working there wasn't really a problem I think the shift cable just happened to be bumping the wiiring harness enough to make it lose ignition. Thanks for the new outlook on hints to check.

 

[merc850]

Re: Merc 1000 not getting spark, checked everything I know need pointers

Good job!
I solder my connections and cover them with shrink-wrap tubing; the butt-connectors
can corrode over time and rot the wires.

 

[merc850]

Re: Merc 1000 not getting spark, checked everything I know need pointers

Good job!
I solder my connections and cover them with shrink-wrap tubing; the butt-connectors can corrode over time and rot the wires.