Autoprop and Yanmar

[alan]

I have recently fitted an Autoprop to my Ben 343 which is fitted with a Yanmar 3YM30. Now, I used to have an Autoprop on my last boat which was fitted with a Volvo and I used to leave the gear in ahead whilst sailing; this seemed to work OK without any problems.
Autoprop in their general instructions recommend to stop engine in ahead.
However, I seem to remember that with the Yanmar it is not recommended to leave transmission in ahead (with a fixed prop) as this causes the gear train (cone?) to 'lock'.

So, what does the forum recommend for the Yanmar/Autoprop configuration ....... should I leave it in astern??
Thanks for any advice.

Alan.

 

[radio1]

Hello Allan

I also have a ben OC 343 but she is fitted with a Flexo fold 3 blade folder. We put the gearbox into reverse after stopping the engine, this has been discussed quite a bit on the 343 forum HERE

Have not noticed any problems so far by using the reverse gear when sailing so far

regards
franky

 

[alan]

Thanks for the link, Franky.

Alan.

 

[charles_reed]

Why not ask Autoprop - they'll almost certainly advise leaving it in forward gear NOT reverse, and the idea is that the cone locks the prop so that the blades trail into the minimum resistance attitude.

Now whether a fixed or rotating prop produces less drag is a totally different kettle of fish - though probably the original Wolfson Institute research is the most definitive.

 

[alan]

Thanks Charles; I have already e-mailed Bruntons and am waiting for a reply but thought that someone on here may have already figured out the "correct" way of operation.

Alan.

 

[Robin]

We have a Yanmar 4JHE 44hp with a Brunton prop and always stop the engine in forward whilst still moving and it doesn't lock. Our last boat had a Volvo MD22L and we did the same but the gearbox did lock, however a quick blip on the starter (1 second) would free it, put it in neutral and Bob is uncle Robert. So I would adopt the same method with any gearbox if it did stick.