Twin engine boat... The problem started a few days ago. Noticed when starting the engines that the port engine when cranking over to start was much louder and higher pitched when starting vs. the starboard engine. I can't figure out or even start to imagine what the issue could be but never had any issue like this prior. Any ideas? Otherwise, it's running great and no odd noise when running. Sounds to me like a noise from the valve area of the engine but they only have about 425 hours, so I'd be surprised if there was a major issue.

Mine sounded like that last year about mid season with about the same hours as yours...it was the starter..

Ayuh,.... My 1st guess is a dyin' starter, or it's bolts are loose or broken,....

Thanks for the suggestions. It turned out the starter is loose. Now to try to gain access to tighten it! Should be fun!