Water MUST MUST be way above the Cavitation Plate. I would use 8 to 10" above it. Did you accidently trim the motor up too high ?
The impellor may be slightly worn if run long enough. You may have been sold the wrong impellor.
IF you do it correctly ? Then you will never have a marina part timer NOT DO IT CORRECTLY. And then say.......... WE did it right.
Been there.
I have never used antifreeze in anything I own. Except cars. I run carburetor dry and drain water. I do check all oils for getting some...
How run down the battery is. Really determines the RECHARGING current being supplied to it. Assuming all the electrical parts are in good condition. What type of chemistry is your battery ?
Do not use toilet bowel cleaners. They are VERY VERY strong corrosive chemicals. They will drip on to Aluminum and eat it alive very quickly. EXTREME caution if used. Must have a pressurized garden hose next to the cleaning area.
A 20 FOOT storm sure is now predicted. Path looks like all of Florida west coast is getting a 4 level and the record water storm surge.
RUN AWAY !!!! While you can.
Getting the tube into correct hole can be a several attempts. To get it into the hole correctly. I had to slightly bend the tube To line up almost perfectly. A slightly frustrating job.
A slightly, occasionally, sticking open valve can cause that slightly different engine sound. We are being forced to check out really RARE causes.
I forget. Does that sparkplug look bad after the crack forms ?