1979 Johnson 150HP V6 150TL79C Starting Issue

[geneno2u]

Hello. I am hoping someone could provide me with some insight. I have a 1979 Johnson 150HP V6 150TL79C. I purchased it with a pontoon on 28 Dec 2015. The day I bought it I brought it out on the water. It ran great. I brought it home and started changing things on the boat to fit my likes and dislikes. I ended up rewiring the power lines and replacing the batteries with Marine approved batteries.

I tested the motor about 3 months ago. It started and ran for about 10 minutes and I turned it off. The following weekend a buddy and I took a trip to the lake, but it in the water and I ended up killing the batteries trying to start it. It turned out both Marine batteries I had were dead.

I replaced the batteries under the warranty. This time when I attempted to start it I couldn't get the motor to turn over. I ordered a service manual for the motor and began reading up on the process or repairing it.

I looked at the fuel but didn't appear there was water in it. It would stutter try to turn over, pop some exhaust, etc...
I looked at the Coil Packs and noticed they were cracked really bad and looked like there was some sort of sticky liquid coming out of them. I read many different forums that said they may be repaired if not too bad but it was best to replace them regardless.

I ordered 6 Sierra 18-5176 replacement coil packs. I removed the original coil packs using the information in the service manual.

After finishing the install I started the engine but it had a different sound to it when starting. There wasn't any exhaust this time either.

I checked the spark plugs with a newly purchased gap tester but the tester kept falling apart on the ground clip and I had to reset the spring every couple of times. I couldn't get it to spark. I ended up doing a resistance test on the coil packs and spark plug wires and all of them registered between 274-280. I didn't see information in my service manual about where the resistance should be.

The thing that confuses me about this is I didn't bother to test the spark prior to changing the coil packs but based on how it is responding I am guessing that I did get power and now the plugs do not.

I tested the resistance on the Power Pack as well and the manual states there should be a higher resistance number on the D ports in the plug and a lower number on A,B, and C ports. When I tested it I got .001 for A,B,C and 1 for D. I wondered if I tested it wrong. I also did not see information in the service manual about where the resistance should be.

I started to wonder if the plugs on the coil pack are not making a connection with the plugs on the Power Pack. I did not use Dielectric Grease. Should I use it on the plugs? Is that safe? I also did not put any on the wires or spark plugs.

Side Note: I did notice a very small fuel leak on my Fuel Pump/Filter. I ordered a gasket kit for it.

Does anyone have any suggestions about what may be the issue or if I am doing something wrong? I was debating on just purchasing some used power packs to test with but didnt want to waste money.

I attached some photos of the coil packs and spark plugs.View attachment 14670View attachment 14671View attachment 14672View attachment 14673

I've got 150TL79C, from the sound of your video you got either choke problem or you spark advance is defective also do you have butterfly springs on carbs also to keep them open. Mine was basically doing same thing as yours check the manual choke lever also take hood off. Spark advance if connected to throttle lever if their old they could've broken and you wouldn't know it