I have a yanmar 3hm with 1500 hours. Recently noticing chirp/tweet noise at low rpm/idle. Noise goes away at higher rpm under load or no load. Belts are tight and water pump">raw water pump just rebuilt. Any ideas what this noise might be? And how to tell? Thanks in advance.
I think it’s normal for a loaded down alternatorcharging the bank, I know mine does it, I have a serpentine belt. Watch for belt dust, that may indicate a worn belt.
The serpentine belt kit from Electromaax was one of my best boating buys ever. Works a treat. No more dust everywhere. No more constant belt replacement. No more squeals. Really helpful company too.