what is on the bottom now? is it black ablative anti-fouling? or a colored bottom paint?
why was your bottom painted if you have a trailer boat? did you buy a boat that was previously moored?
if you have black ablative paint on their now and you clean it and then recoat with 2 coats of...
if you ran the motor for any length of time (longer than a few seconds) without the water lever being way above the impeller, you may have toasted the impeller.
inspect that transom and the stringers for rot. while the motor may run, old fiberglass boats often need lots of work.
the most expensive boats are the ones that are free or close to free as they need the most work.
what troubleshooting or diagnosis have you done. As indicated above, you will have to look to find the problem. could be bad wiring under the cowl, could be bad wiring in the boat, could be a bad enrichment solenoid, could be a bad switch.
dont look to facetube. most of the info is wrong. look in the stickies on this forum. however a failing lower shift cable will delay its action often causing stumbling and in some cases killing the motor while shifting (use google to search for the string "lower shift cable iboats.com" and...
Start googling Mercruiser 470 issues.
If your original voltage regulator still works, no need to change to an alternator.
However if the motor overheats as much as 10 degrees, that motor will eat the voltage regulator and spit the head gasket
