Engine Oscillations

[Juliet 15]

Hi all, I've been observing a very small oscillation in the stbd engine (DD 4-71N, Glendinning synch, Hat 58LRC). It's been going on for probably a year. I set 1300 rpm to cruise, and after about 1 to 2 hrs the stbd engine will "hunt" by about 25 rpm above and below the port engine. If I set the rpm to 1400 or 1200 it goes away. It's not an issue, except it's an audible rpm change.

Any ideas?

 

[Greg QS]

Engines "hunt" for various reasons. Normally in no load . Under load, could be a few things.
Start with the simple stuff. Fuel restriction. Change filters and for fuel air leaks , Second check the Glendenning cable , It could be restricted. Check first then we move on
To determine if it is the glendenning, when it happens , turn off the sync and manually set the throttles, If it continues it is not the Glendenning.

Start there and we can continue.

 

[lwarden]

Good advice from Greg above. Also, check for a sticky cable or loose fitting which secures the cable sheath or end fittings. If there is a lubrication maintenance on the lead screw of the motors, perform that and see if it improves.