Won’t keeping the transmission in neutral cause the prop to rotate (as it is not ‘connected’ to the engine and thereby increasing the chance of a prop shaft wrap?
Neil FoxFire, C&C32 Worton Creek, MD From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Martin DeYoung Sent: Tuesday, March 26, 2013 2:47 PM To: cnc-list@cnc-list.com Subject: Re: Stus-List Feathering a Max-prop On Calypso with its Perkins 4-108 coupled to a 71 series Borg-Warner Velvet Drive reduction gear we mostly do 1. & 2., but sometimes 3. With our Velvet Drive reduction gear, the MAX prop feathering process needs the engine running to provide the hydraulic pressure to brake the shaft (hydraulic pressure continues for a moment as the engine shuts down). The motoring/sailing speed provides the water flow to push the prop blades into the feathered position. After the engine has been off for a few moments the Velvet Drive no longer has enough hydraulic pressure to lock the prop shaft negating any effect of the gear level position. It is important to know what your own reduction gear manufacturer says regarding sailing in neutral vs. in gear. With a feathered MAX prop the prop shaft should not rotate whether the reduction gear is “in gear” or out. If you hear a rumbling noise after “old smoky” has shut down the prop may not have feathered correctly. Once in a great while, or after I have just serviced the prop and it is full of grease, I will need to start the engine back up, use reverse gear for a moment then back to forward and repeat feathering process. On occasion, especially when using a spinnaker, I place the throttle/gear lever in the neutral position to avoid having a spinny sheet wrap around it. (Calypso’s throttle/gear lever is located stbd/outer side of the cockpit just below a cleat used with the primary winch.) Martin Calypso 1970 C&C 43 Seattle From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Terry Sent: Tuesday, March 26, 2013 11:03 AM To: cnc-list@cnc-list.com Subject: Stus-List Feathering a Max-prop How do you feather a max-prop? A friend of mine says he: 1. While motoring forward at 3 knots, shuts off the motor 2. Places the transmission into reverse to feather the prop That’s it, that’s what he does. He leaves the transmission in reverse. I do the following: 1. While motoring forward at 3 knots, shut off the motor 2. Place the transmission into reverse for 20 seconds to feather the prop 3. Place the transmission in neutral According to my friend, leaving the transmission in reverse keeps the prop feathered and keeps the driveshaft from rotating. Any thoughts on this?? Terry Johnson S/V Ozymandias E-mail: tj...@comcast.net Website: www.tj622.com
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