Yanmar SD20 Saildrive with folding prop - in gear or not when sailing?

[Lucky Duck]

I have previously owned boats with Volvo saildrives where using a folding prop the recomendation is to put the engine in gear while sailing (I usually select reverse), will this be the same with Yanmar's offering?

 

[PhilS]

I put mine in reverse to stop the prop and then back to neutral. I can clearly hear when the prop is turning, and once it has stopped it doesn't start again until I use the engine. I have a Flexofold 3 blade prop and it works well.

 

[Concerto]

The purpose of a folding prop is to reduce drag. By folding the blades it should no longer turn. So make sure you are travelling fast enough (about 4 knots) to close the blades, either just after switching the engine off or whilst sailing. Place in gear with the engine off and once folded, move to neutral.

 

[snowleopard]

I have Yanmar SD20s with flexofold 2-blade props. I always leave mine in ahead while sailing. I started off thinking that when closed they wouldn't turn but trying to sleep in a bunk on top of the engine soon disabused me of that idea. The blades are not symmetrical when folded so water flow turns them if out of gear. Judging by the rumble, they turn at about 1 rev per sec at 7 knots and the noise would drive me crackers in short order.

Some have said it damages the gearbox to keep it in gear but I've been doing it for 15 years and 20,000 miles and everything still works fine. It also has the virtue of being ready for action at a moment's notice - turn key, hit starter - engine running and in gear. I can be under power in <2 seconds!

It may be the case that a fixed-blade prop could cause damage if left in gear but they apply vastly more torque than a folded prop.

 

[Lucky Duck]

Thanks, that is an identical combination to mine.

In places where the tide run strongly I have heard the prop rotating while the boat is moored and the engine out of gear but only noticeably with the stern facing the tide.

 

[Sailfree]

Some have said it damages the gearbox to keep it in gear but I've been doing it for 15 years and 20,000 miles and everything still works fine.
It may be the case that a fixed-blade prop could cause damage if left in gear but they apply vastly more torque than a folded prop.

I have Yanmar Gearbox and found rotating prop noise annoying. I started to lock prop by engaging astern when sailing and found could not move gear lever to neutral to start engine. Engine had to be started in astern. Phoned both Jeanneau and Yanmar and both said sailing with a fixed prop in astern will damage the gearbox.

For this reason I changed to a feathering prop. I now lock in astern but can change to neutral once prop is feathered and gear change mechanism is not locked up as it was with a fixed prop.

My understanding is that boats built for the US markets the engine cannot be started when any gear is engaged so a bigger problem for them if they engage astern when sailing with a fixed prop