1972 7.5 hp bogging down in forward gear full throttle

[Nicktr23]

If anyone can provide insight on this. Motor ran fine in the tank at home. I want going full throttle in gear. Motor has full rpm when in neutral. But when I put it in forward gear and give it full throttle, rpm drops. Please see video attached. Carbs recently cleaned. https://youtu.be/ZwXkSMQqAOg
from my research online, pointing to bad crankshaft seal? Thank you for any insight.

 

[RCO]

I would almost guarantee you are running on one cylinder . They will run surprisingly well on one cylinder until you put a load on it . Do a cylinder drop test to see which one is causing you problems. The phasemaker ignition on those can be finicky and some of the parts are $$$ .

 

[Nicktr23]

I think you're right. I went to check the red coils and see that one of the coil had wire that is stuck by the flywheel. As the flywheel turn, it rub against the cable. This cable connects on the positive terminal of the coil. Do you think that did major damage?

 

[Nicktr23]

Here is a picture of the wire that was rubbing on the flywheel. The other insulation is very brittle.

 

[racerone]

Simple test for ignition maximum output.----Does spark jump a gap of 5/16" on both leads , yes or no.

 

[Nicktr23]

I will test once I assemble the outboard. I broke the swivel bracket that day as I forgot to tilt the motor up while using the main motor. For a second there, I thought my small boat 12 ft Valco was going down or I would lose the engine.

 

[Nicktr23]

I have good spark on cylinder 2 and weak spark on cylinder 1. I started the engine and removed the spark plug on cylinder 1 and it was still running. Repeating the same for cylinder 2 and the outboard stalls. This suggests to me I was only running on on cylinder. The frayed wire was from the 2nd coil. I then pull off the flywheel to inspect the points and the insulation blocks. The insulation block that has a wire going to ignition coil 1 is cracked into 3 pieces. Then other plastic block is cracked too but not as bad. So I order 2 new insulation blocks and hopefully that will solve the problem. Nothing else I can think of. The high speed and low speed coils looks good and checking the ohm is good.
question- the two green wires coming out of the stator goes to the negative side or positive side of the ignition coil???

 

[Nicktr23]

Hopefully these are the reasons why the motor not firing in top cylinder. When detaching the spark plugs from the top cylinder, I feel electric shock.