Boat ignition

[Goofy420]

I have a 1976 mercury 1150 that won't start. It died at the lake couldn't get it re started. The next day it ran and now nothing. I tested the switch box a few times and get different results. One day I get spark one day I don't. When I do get spark the motor turns over but won't start. It does have 12.9v at the red and white terminals on the right side. I just would like to know which 400$ part to replace so the damn thing will run.

 

[Chris1956]

The CDIElectronics web site has a simple test for everything but the trigger. Run the test. If you get spark during the test, the failed part is likely the trigger. The test assumes the coil is good. Most are.

 

[Goofy420]

The CDIElectronics web site has a simple test for everything but the trigger. Run the test. If you get spark during the test, the failed part is likely the trigger. The test assumes the coil is good. Most are.

I did, a couple of times and got different results. It is hit or miss with the boat starting as well it will start one day and then won't start the next.

 

[Chris1956]

The engine wiring harness on those age motors can be intermittent. They can be hot wired pretty easily. I would recommend you jumper from the battery directly to the red and adjacent white terminals on the switchbox, and ground the block to the battery as well. Then run the test again.

If you get consistent spark when running the test, the trigger is likely bad. They can be intermittent as well.

If you have consistent spark and she still won't start, make sure you are choking the snot out of her.

 

[Goofy420]

The engine wiring harness on those age motors can be intermittent. They can be hot wired pretty easily. I would recommend you jumper from the battery directly to the red and adjacent white terminals on the switchbox, and ground the block to the battery as well. Then run the test again.

If you get consistent spark when running the test, the trigger is likely bad. They can be intermittent as well.

If you have consistent spark and she still won't start, make sure you are choking the snot out of her.

Could the solenoid be bad? I did the test and got spark at the coil but no spark at the spark plugs.

 

[Chris1956]

The solenoid only serves to command the starter to crank the engine.

If you have spark at the coil, but not at the spark plugs, either the timing is way off, the spark plug wires are bad, the coil wire is bad or the distributor cap is bad.

There is a carbon electrode in the distributor cap. It is replaceable for a couple of dollars. If it is missing or worn out, you can have spark issues.

 

[Goofy420]

The solenoid only serves to command the starter to crank the engine.

If you have spark at the coil, but not at the spark plugs, either the timing is way off, the spark plug wires are bad, the coil wire is bad or the distributor cap is bad.

There is a carbon electrode in the distributor cap. It is replaceable for a couple of dollars. If it is missing or worn out, you can have spark issues.

It was running good, then just acted like it was loosing spark just cutting off then pick up and go then it did same thing and died. Wouldn't start, just crank over. I did the cdi test on the switchbox and got spark, not sure how strong of a spark but it sparked. Then I tested spark to plugs and one time got spark then tested same plug and no spark.

 

[Goofy420]

The solenoid only serves to command the starter to crank the engine.

If you have spark at the coil, but not at the spark plugs, either the timing is way off, the spark plug wires are bad, the coil wire is bad or the distributor cap is bad.

There is a carbon electrode in the distributor cap. It is replaceable for a couple of dollars. If it is missing or worn out, you can have spark issues.

I cleaned them they all looked good. Plug wires look good no rot or burning, the ends look clean no burned.

 

[Chris1956]

Spark plug and coil high voltage wires should have zero resistance. They are stranded stainless steel. When cranking the motor, ignition on, look (or listen) for spark arc to ground, especially on the lower wires.

 

[Faztbullet]

Check the carbon brush and spring in distributer cap also...

 

[Goofy420]

Check the carbon brush and spring in distributer cap also...

They look good

 

[Goofy420]

Spark plug and coil high voltage wires should have zero resistance. They are stranded stainless steel. When cranking the motor, ignition on, look (or listen) for spark arc to ground, especially on the lower wires.

When I get spark I am not sure how strong of a spark I get. What would cause weak spark?

 

[Dung]

When I get spark I am not sure how strong of a spark I get. What would cause weak spark?

Ground issue