In or Out of gear

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Dave_Rolfe

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Bought a Legend 290 with Yanmar 2GM20F engine and saildrive just over a year ago since which time I have been confused. I seem to see conflicting advice on whether to leave the prop in gear when sailing. Some say do to stop wear on the gearbox while others say don't to prevent wear on the clutch.
Is there a definitive answer as to whether it should be in gear or not please. Confusion reigns at the moment.
 
"a definitive answer ". Problem is on here that you get conflicting advice both claiming to be definitive - it's part of the charm. FWIW my smaller Yanmar gets knocked into reverse when sailing as does the bigger Volvo in a friend's boat. This topic comes up from time to time and I sort of remember that differences of opinion resolve around which gearbox installed.
 
Not sure on the wear issue, but a rotating prop will cause more drag than a locked one.

Check This out to see an explanation. I know it is aerodynamics but I should imagine it is the same for a hydrodynamics

W
 
Wayne is dead right on the drag issue, and why on earth would you let the shaft trail causing unnecessary wear to all components in the drivetrain if you can prevent it?

How can a stationary shaft cause wear to a clutch? Obviously impossible. However quite likely to cause wear when the shaft is trailing if there is any residual contact when clutch disengaged...

You can choose between suffering noise, vibration, wear & drag or eliminating all of these...

Bit of a no-brainer, really.
 
Only issue about leaving it in reverse is that if you sail fast enough you can bump start the engine and the engine will go backwards.
 
Check with the gearbox maual, or manufacturer.

Some should not be left in gear when sailing. Some Volvo saildrives will lock up if left in gear and sailed, it says very clearly in the manual. I know as it happened to me, I dismantled the gearcontrols thinking the throttle gear linkage had broken or jammed, only to find this was fine. If the prop was allowed to spin in neutral there wasn't a problem.
 
You've probably got a hydraulic gearbox. I understand that it isn't a good idea to let the shaft rotate for long periods as the gearbox doesn't get lubricated unless the engine's running. Hence all the malarky with shaft brakes etc.
 
My newish 3-cyl Yanmar engine/gearbox came wth specific instructions from Yanmar to put it in reverse when sailing, which is what I always do. Only problem is that it is often difficult to go back to neutral before restarting the engine, particularly if you have been sailing fast. I quite often thus have to restart in reverse, and then it clicks back to neutral easily enough once running.
 
The owners manual for the VP2000 series states:-

When under sail, the control lever should be in the neutral position if the propeller is a fixed propeller. If the propeller is a folding propeller, the control lever should be in the reverse position. Start the engine and run it for five minutes every ten hours when on long-distance cruises."
 
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My newish 3-cyl Yanmar engine/gearbox came wth specific instructions from Yanmar to put it in reverse when sailing, which is what I always do. Only problem is that it is often difficult to go back to neutral before restarting the engine, particularly if you have been sailing fast. I quite often thus have to restart in reverse, and then it clicks back to neutral easily enough once running.

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John,

there was a long disucssion last year in here about this. Yanmar say it's OK to start it in Gear as long as the revs are low/at tickover. /forums/images/graemlins/smirk.gif
 
Thanks for the description of why drag is greater from a windmilling prop that a stationary one. As a a plain Mechanical Engineer I always struggled with Aero(hydro)dynamics but found the description you posted very clear. It seems counter intuitive that a windmilling prop produces more drag.
Morgan
 
As has been noted, the Volvo handbook specifically states that a saildrive should be left in neutral with a fixed blade prop and in reverse with a folding prop. Volvo do not offer a feathering prop so is silent on this. I have never received a satisfactory explanation for the neutral bit - and it is a pain as anything over about 5 knots and the revolving prop is very noisy, so the temptation is to put it in reverse. If it sticks one can still start the engine and put it in neutral straight away.

Maybe I should save my pennies (lots of them!) and get a folding prop which I am told is silent when sailing!
 
[ QUOTE ]
Thanks for the description of why drag is greater from a windmilling prop that a stationary one. As a a plain Mechanical Engineer I always struggled with Aero(hydro)dynamics but found the description you posted very clear. It seems counter intuitive that a windmilling prop produces more drag.
Morgan

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Why? A fixed prop is another very small part of the boat structure. A rotating one I would have thought introduces entirely new factors of swirl that are bound to interupt a smooth flow.

In a sailing boat it is not the prop that causes drag, but the gap it rotates in, which breaks the flow from hull to rudder.
 
I do appreciate the conflicting opinions and manufacturers' instructions - and concede that locking in gear is pretty damn awkward - BUT ending up moored by the stern to a crab pot in the Looe Channel resolved my dithering; going over the side with a hacksaw in a Spring ebb does NOT feature on my wish list!
 
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