No Start Condition: No spark from coil?

[outgoingjake]

It's a 1981 Mercruiser 898 5.0 305. Boat sat for ~10 years. Mallory distributor system. I believe it is the Alpha One Gen 1 outdrive (still unsure of this though. If someone can lead me in the right direction on how to tell, I would appreciate it).

Coil reads ~8.3v. Engine turns over fine but spark tester is showing no spark to plugs. Coil wire to distributor shows power going through it using a multi-meter. Although, when I hold the distributor end of the cable ~1/2" from ground, there is no spark. Coil also gets hot after a fairly short period of time. I purchased a new coil and that one also got hot, which made me think it is shorting somewhere.

Really lost as I had the boat started for a split second a few days ago. Then we had orange spark, now no spark.

We have re-done wires, checked grounds, checked the 4 cables going to the ignition, replaced coil, replaced spark plugs, replaced condenser and cleaned points in distributor, and ensured distributor cap and rotor are in good condition.

I looked at the service manual to ensure wiring was correct going to the coil.

Any help is appreciated. Dad gave me the boat for free and said if my friends and I can fix it we can have it. Have slight knowledge on some of this stuff but I've exhausted my knowledge and that of what I could find using google.

 

[Bondo]

Mallory distributor system.

Ayuh,...... File, 'n set the points,.....

 

[outgoingjake]

Ayuh,...... File, 'n set the points,.....

I will give that a shot tomorrow afternoon. Thank you for the help.

 

[achris]

Here's a thread worth reading as it's a points system with no spark. Don't worry that it's a 3 litre 4 cylinder engine, the ignition system is the same as yours, and so are the diagnostic and repair procedures.

https://forums.iboats.com/forum/eng...tdrives/10863021-no-spark-1987-3-0-mercruiser

Chris.........

 

[Scott Danforth]

all points need to be filed if they sat unused for any length of time.

even new points

as stated

file them
gap them
verify the dwell
then install the cap/rotor
fire it up and set the timing

this is covered in the stickies at the top of all the engine forums.

the great thing about this site, you dont need google for answers, you just need to read the stickies. about 90% of the answers to your questions are there.

since the boat sat for 10 years, you also need to clean out the fuel system, this means cleaning the inside of the tank, flushing the lines, verifying the anti-siphon valve is operational, checking the fuel pump and cleaning the carb.

being a 1981 boat, you may want to look to see if the stringers and transom have any rot. its 40 years old and most boats are designed to be replaced after 15-20 years old.

 

[outgoingjake]

Thank you everyone for the replies.

We purchased a new point and installed it. During installation I found that the ground wire was not being separated properly from the dist. housing, so I put the plastic spacers that were already there against the housing to separate the grounds.

I believe the spacers not being correct was causing a constant ground, which led to no spark at the points.

Boat fired right up. Thanks again for the help!

 

[outgoingjake]

So, it started once, and is now no longer sparking again. If I reset the points, it will spark again a few times and stop again. Any ideas?