Engine iddle speed

[Mikenda]

I have a Volvo MD22L with shaft drive. After a run of several hours when maneuvering into my berth the engine vibrates on its mounting when going from neutral to either forward or reverse, an increase of revs stops the vibration. This symptom does not occur on a normal days local sailing with an average engine run of two by 30-45 mins to and from my berth. Any ideas please?

 

[Evadne]

Sounds like it may be a resonance at a particular engine speed, and the engine only reaches this at idle when it is well and truly warmed up? Assuming that there is no untoward cause for this, such as an engine mount detaching, or the wrong size of mounting block, you could try reducing the idle speed, but not so much that it won't idle when cold, or failing that increasing it a touch.

 

[Landale]

I have the same problem - ish.

Volvo 2003 and its tickover is just as you describe, it seem to want to tick over at 650 rpm rather than 800 these days. There's no fuel shortage etc, I'm wondering whether it just requires an adjustment to the stop on the throttle cable.