ok that's different then what I thought with 5 blue plugs
You have only one plug
https://www.mercruiserparts.com/bam/subassembly/31503/13808/200
In that case, your playing with maybe's
Maybe all the water drains out, and maybe it doesn't
Fresh water boats have less of a chance to not drain...
Moved you to OMC, it's not a prop issue it's a drive or cable issue
Lower shift cable is disconnected/broke/out of adjustment
Does shift plate move when throttle is moved FWD/REV?
Don't of any vids I would recommend, but it's fairly easy
Not getting into the oil change or other stuff, just winterization of motor
Remove block drains on each side of the block. Use a screw, nail or wire to push up inside the hole to make sure nothing clogs drain hole
Remove exhaust...
The tanks use a float with reed switches, and pressing the water or holding tank buttons sends power to that float. Need to check for 12V to the push button switches
Welcome
If VP says they should be replaced, then my guess is yes.
That said, you can try to use old ones and if it works out your good. Don't know what motor but if injectors are easy to get to then might be worth a try
Welcome
And the 2 Mech you found don't go back to them, especially the 2nd. First replaces starter and 2nd does same thing, good grief
My first guess with on/off and no power is the key switch, next would be bad connection. Easy to find with a voltmeter
We're back were we started.
The only way fuel comes into the clear hose is if pressure is to high, needle and seat not stopping fuel or float level is set to high
Good point on VL
Did not think about it because of no mention of it happening after a run.
Does this happen after the motors been running for a bit or is it when its cold and not yet warmed up?
Don't know where the Bat is tapped in your boat, have to trace wires to find out. Most come off the starter solenoid post, others off the Bat
The fuse block will have one main wire feeding it, follow this back to where it connects