TOPIC: Engine failure...I'm stumped!

So a week ago I put the boat in idle while the kids swam and then turned it off. When I tried to start it, it wouldn't. It turns over fine with the starter but no ignition. I replaced the coil before we went out on the lake, but that obviously was not the issue. Yesterday, I replaced the plugs and checked all the wires. There is no sign of arcing in the distributor cap. Also, I rebuilt the carburetor but still no ignition. I'm wondering if it's the generator? Anyone have any ideas?! (It's my volvo penta bb70)

If you are sure the distributor is firing (check the plug wires with a timing light) then it must be a fuel delivery issue. My guess is that you either have a bad fuel pump or some kind of fuel line obstruction. Remove the fuel hose from the carburetor, stick the end in a glass jar and have someone turn the engine over. If it pumps fuel into the jar, it's not the fuel pump. (Check the gas in the jar for crud.) If OK so far, pour a little gas into the carb and try to start the engine. If it starts, you have a bad carb, choke not functioning or maybe just a linkage issue. (All this assumes that the distributor is still in time and hasn't moved.) Good luck!

I checked for spark and am not getting anything. So could the distributor be bad? All the contacts in the distributor cap have burn marks. I traded the cap out for a new one and traddd out the rotor but still no spark

Also I don’t see how it could have moved so I don’t think it’s a timing issue?

I would suggest checking the position of the Lanyard Safety switch.
Then check and see if you have 12vdc when the ignition key is "ON".
Then just how much voltage is reaching the points.
doc

Hook a 12V jumper up directly to + side of coil (side that does not go to distributor). Then check for spark again. If spark, problem is from key switch to coil. I assume that engine has a ballast resistor or resistor wire but probably also has a ballast bypass. If so, it should start & die when key is released if ballast is bad.
Another thing to look for is a bad rotor with arcing burned thru plastic allowing the spark to go to the distributor shaft instead of out to the plugs. But this usually only happens if rotor has solid center contact & spring loaded center contact in the cap.

That's good advice. If it's a no-go after wiring a jumper from the battery (or any other hot source...starter cable, etc.), run a jumper on the ignition switch from BATT to IGN. Turn the ignition switch. If it starts, you have a bad ignition switch. If not, you have a bad wire from IGN to the positive coil terminal. If none of this works, it might be time for a hammer.

I’m wondering if the electric ignition is the problem. Motor turns over fine, but no spark. I replaced the points with electric ignition when I restored it 7 years ago

Every now and then the push button wouldn’t start so I’m wondering if that could be the issue too. However it works fine to turn over the engine.

Pic of dash

I reread your post. This is the 1st time I see where you had installed an electronic ignition. Are we talking Petrolux? I don't like them, I still run points/condenser.
Regarding the timing, if it somehow changed you would still have spark, just at the wrong time.
It sounds to me as if you are a bit mystified by a distributor. Find an old timer that grew up with conventional ignition (automotive is OK, doesn't need to be marine) & you'll have spark soon.

Pull the tach wire off the negative side of the coil, I have a tach go bad internally for what ever reason and it grounds out the coil. No sparky sparky. Pertronix are good have used them for 30 years.