1973 70 up Chrysler won't start

[bleach68]

Some background... top 2 cylinders have 125 psi couldn't get tester in bottom cylinder. New to me motor. Supposedly ran but no spark put with coil with built in resistor and added condenser.... still had no spark so checked points and they needed setting. It then had spark and ran. Set static timing and took the boat out for a test run. Ran good but needed adjustment for shifting. I did some adjusting and also checked level in lower unit by sticking in a piece of wire in the top fill hole. It came out with grease on it so I figured it was filled. I had the boat tubing for 3 hours and stopped for supper and couldn't get it started again. After getting it home I checked the lower unit and drained it but to my surprise no oil drained out. I have filled it and checked the fuel pump. It pumps fuel when cranking over. It has spark at no. 1 cylinder when cranking. It appears to have a key in the flywheel keyway and when sticking a small screwdriver down the keyway it hits what I guess is the key. Even with a spray of quick start it does not want to fire. Maybe the key is sheared?? Not sure what else it could be but I welcome any suggestions!! Thanks
I also added a telltale and had put a new impeller in. It pumped water good the whole time it was running.

 

[Nordin]

Check the flywheel key, it is easy. Set the throttle at idle, take out the top spark plug.
Put a screwdriver in the hole and rotate the flywhell until the screwdriver is pushed out farest distance.
If the curve at distributor pully lines up with the flywheel rimm and the TDC zero mark lines up with the zero mark at timing tab the timing is correct and the flywheel key okey

 

[bleach68]

Flywheel key is OK then ! When I refueled I used a Native gas station -- a possibility of water in the gas , but it doesn't want to start even with quick start!! Not sure what to check now!

 

[bleach68]

Update! On a whim I switched back to the original capacitor discharge ignition that I thought I had tried when I shorted out one of the cables. To my surprise When I removed and grounded the correct plugs there was spark! So I redid timing and put some gas treatment in the tank and she is running nice! Pumping water good and starting nicer than with the auto coil!! Just looks like I need to check driveshaft seal as there is some oil around seam to lower unit. Thanks

 

[jerryjerry05]

"Driveshaft seal"
The oil is usually just unburned gas/oil.
When tinkering with these everytime you turn it over it puts fuel in the cylinders.
It doesn't burn and leaks down and onto the ground.
Usually not a problem unless it's gear oil.

 

[bleach68]

I ran it in the lake today....ran good up until just a past half throttle where it would start skipping. Worsened at full throttle. Perhaps I am a little off on the timing ?? Or could a bearing in the lower unit be fried from the running with no oil??

 

[jerryjerry05]

The "skipping" is it a miss or is the gear banging ??
​The clutch dog could be bad if the lower unit is jumping.
It usually makes a thumping or bumping noise.
It can also make the boat shudder when the dog slips.

If it's the dog??? You can try flipping the dog around or grind the edges off.
Remove it and post pics of both sides of the dog and forward gear.

Do a static timing and don't change anything unless your sure it's off.
The timing doesn't usually change unless someone tinkers with it.

 

[bleach68]

I have set the timing using a timing light and ground g the plugs but did it from the side of the motor so I may be off. I will recheck it. It did seem to shudder when it would stutter and there was vibration. I have another lower unit to throw on and will recheck. Thanks for your help !!

 

[bleach68]

Hi, I dropped the lower unit after removing the prop and split the casing after draining the oil. Inspected the gear set and bearings and removed the roll pin from the dog and flipped it around and reinstalled it. Going to take it to the lake in the next couple of days and see if the high speed shudder is gone!! Fingers crossed!!