Yamaha 70 took on water. Drained everything and it ran fine in the yard. But now, even on a charger it won't turn over enough to start.

If it worked before the stereo, look for burned fuses. Check for a.c. signals at the coils and injectors. Is there fuel pressure at the schrader valve on the fuel rail? Try scanning the computer for hints.

remove the carbs and have them professionally overhauled
indicates a problem in the high speed circuit , probably a blockage
might also be an incorrect float level that is not allowing enough fuel into the bowl for hgfh speed operation

Previous owner had way overfilled crankcase oil. Oil had gotten into carb and clogged air filter. Drained oil to correct level. Ran engine but kept cutting off-see above. Took off carb cover cleaned housing and ran without air filter-ran fine. Unsuccessfully tried to clean air filter with gas-did not work. Apparently, the engine could run just long enough to exhaust the air in the old filter and cut off which is why it would start back up after a few seconds. Bought new air filter-whole thing-about $15 at Carquest. Put in some carb cleaner and installed the new filter and it runs perfectly.

have you checked brushes on motor

try a new spark plug

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It could be the starter, but I would check battery connections and voltage. When you turn the key on, there may be enough power to turn the lights on, but not enough power when the starter switch is engaged. Also, you

Its possible you got water or dirt in the gas when you filled it up.
Or it could be a coincidence and the problem is something electrical.
I would want to know if all 4 plugs are firing and what kind of fuel is coming thru the injectors. You should be able to spray carb cleaner into the throttle body and make it try to start if all cylinders are firing.

Take direck power from bat to the problem.If works its a open circuit .Els trace weiering from the problem to the power sauce. Test fueses seperate.

It sounds like some of that water turned to steam in the engine and the pressure of the steam did some damage. Check out the timing chain and the timing mark alignment. Check out the valve condition...there might be some chipped or cracked valves...yikes!

Drained the water from the tub into a bucket. Since the water flowed through the disharge tub I knew there were no obstructions in the line. I then took took the discharge pump out and took it apart. Turned out to be a bobby pin in the motor that was jamming the impeller.

Put it all back together and it works just fine. Took me about 2 1/2 hours total to diagnose and repair.