89 3.0 mercruiser, cranks won't start

[natsgrampy]

Had boat in Cape Cod Bay for 6 hours ,no problem. Hooked it up to muffs to wash out and no problem starting. That was a week ago. Today try to start and just cranks and won't start. Checked in carb and it's getting fuel. Seems as though there is no spark. Pulled a plug and held it up to block and had someone turn key as if to start and cranks but can't see a spark.

Checked the voltage at the positive side of the coil and it was 11.36 -12.05 with key in run position.

Took off distributer cap and all looks well. There are new points, condenser, rotor, cap, plugs and wires installed this year. Checked the shift interrupt and that seems to be in correct position. This is a conventional ignition system.

I just purchased a spark tester and am going to hook it to the plugs to test them and then the coil to see if it sparks.
Can the spark tester be used the same way as used to test a plug, to test the coil? If not, how would I check the coil to see if it is working properly?

What other items can I check before I start replacing items?

 

[natsgrampy]

Re: 89 3.0 mercruiser, cranks won't start

OK here is an update, checked for a spark, on #1 plug and there didn't seem to be a spark. Thought I should hook up the muff to water so as to not harm the new impeller. I went back and tried again and lo and behold, there was spark. I put the wire back on the plug, tried to start and vrrrrrroooooooom. It started.

Do I NOT have an issue, or, is there something I need to address before going back out on the water?

 

[Don S]

Re: 89 3.0 mercruiser, cranks won't start

Can the spark tester be used the same way as used to test a plug, to test the coil?

Yes, or you can just remove the coil wire from the distributor cap and hold it 3/8 to 1/2" from a good ground and see if you get a bright blue/white spark when you crank the engine.

PS: 12.0 Volts or less is a dead battery. Charge it up.

 

[natsgrampy]

Re: 89 3.0 mercruiser, cranks won't start

Pulled the distributer cap and one of the screws seemed loose. checked the connections to points, condenser. removed and inspected rotor. Replaced them and she started. I'm thinking the cap being loose a little was the cause of no spark. Hopefully that's the answer. Any thoughts?