Low Idle

[GTN]

Got a problem on my SeaRay 340 (2004). She has the 6.2 Mercs installed. When started, and at any point when at idle, my rpms on both sides are running around 525-560. I get a lot of gear rattle when trying to leave/enter marinas and stall out regularly if underway. Is there a way to increase the idle setting so the engine will idle around the high 6 to 700 range??

 

[Fred]

If you have not changed the IAC mufflers, I would start there.

 

[cfd95]

or IAC valves/tune up
Dead cylinders will cause low idle and chatter from the coupler.