Yanmar 6lya surging

[Scubawpb]

My Yanmar 6lya surges at idle after a long hard run. It doesn't stall and can be accelerated normally. Any thoughts?
TIA, Tony

 

[Ski in NC]

What's the idle rpm? If set too low it can surge. If you just barely crack throttle, does surge go away? I think these like around 700rpm as hot idle. If at 600, surge is possible.

 

[CaptSteve53]

Absolutely Correct- Normal low speed idle is 700 RPM for these engines


Cheers Steve