Re: Sharki shaft alternator

Warren Traill

Thankyou Olivier. Your explanation is abundantly clear to me and a relief to know that my practise of engaging reverse while sailing has been the right one.




From: [] On Behalf Of Beaute Olivier via Groups.Io
Sent: Tuesday, 12 March 2019 4:13 PM
Subject: Re: [AmelYachtOwners] Sharki shaft alternator


Hello Warrren,


on a Sharki with fixed prop, while sailing, you should stop the propeller by engaging reverse. This will reduce noise and packing stuff wear. There will be a "clunk" which could surprise you but don't worry, the clutch shock when you engage forward or reverse with the engine  ON is stronger (there is more power from the engine towards the propeller when it is running  than from the prop to the engine --through the gear-box--when the engine is OFF).

This true for every boat with a fixed prop and mechanic gear-box.


For those with Autoprop and mechanic gear-box (mainly SMs), they engage forward in order to stop the prop spinning. They don't necessarily need to start the engine with forward engaged.

For those with Autoprop and hydraulic gear-box, they leave the throttle lever in neutral position, the shaft brake system doing the job.

In both, while sailing and as the engine starts, the Autoprop will spin before forward is engaged. This is not a big deal BUT it is better to drop boat speed (if possible) before engaging forward. This will give a smaller shock to the gear-box and soft coupling.


I'm not sure if this is all clear to everyone, so, feel free for questions...



On Monday, March 11, 2019, 11:30:23 PM GMT+1, Danny and Yvonne SIMMS <simms@...> wrote:



Hi Mark,

the important thing is the clunk. My sign says no to forward, but as I said in my previous just to be contrary sometimes its clunk in forward, sometimes reverse. I don't think it has anything to do wit the prop. I have auto prop So I just go with the clunk.



On 12 March 2019 at 07:58 Mark Erdos <mcerdos@...> wrote:



The opposite is true on Cream Puff. There is a French sticker by the throttle that says to put the gear in forward when sailing and leave it there. We do not have a shaft break or alternator. We also start the engine (when the boat is moving forward) with it in gear per the sign. This seemed odd to me but Miles from Lady Bug has the same sticker and speaks fluent French.


We are fitted with an AutoProp and for some reason this makes a difference (and of cause the engine on Amel faces the wrong way – not sure if this also effects it). We are unable to stop the rotation of the shaft in reverse. It will still slowly turn. We hear the reassuring clunk in forward and the shaft will not move. I really do not know all the mechanics involved but just follow the sign.


This all obviously varies by vessel, engine, prop etc.



With best regards,





Sailing Vessel - Cream Puff


From: [] On Behalf Of Danny and Yvonne SIMMS
Sent: Monday, March 11, 2019 2:39 PM
Subject: Re: [AmelYachtOwners] Sharki shaft alternator



The reason being that it locks in reverse but in forward the clutch plates are lightly engaged and the propeller turns slowly causing wear to the plates. Try it with the engine cover up when sailing with the shift in neutral and the prop will be spinning. Engage forward and it will slow, engage reverse and there is a satisfying clunk and it stops.

However mine for some reason not known sometimes stops in reverse, sometimes in forward so I always check for that satisfying clunk.



SM 299

Ocean Pearl

On 12 March 2019 at 07:18 Ian <parkianj@...> wrote:

The Santorin has a Hurth gearbox. The instruction by the gear shift says not to put into forward gear whilst sailing. Must be a reason.






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