Re: how long to fix spun bearing
If they just sold a rebuilt engine they got from a vendor then they have to get that vendor to fix or replace the item before they can re-install. That vendor may require an inspection of their own first to determine the cause of the failure and determine if it is covered or not. Also the warranty is for the goods and does not give any timeframe that it has to be fixed inside of. .
They may have 3 boats ahead of you that bought engines after you did, who knows. All they really owe you now is a status report of where they are in the process
To try to answer your question: The actual work from engine removal, teardown, re-assembly and re-install and engine run-in could be done in 2 days if the parts were ready and nothing else showed up as wrong in the engine. But again, they have to inspect it to make sure how it happened and if it is covered (damage was not from abuse), and if another vendor is involved then the time taken will most surely double or triple as their authorized return policy and process is engaged.