Hello everyone. I got a 1979 S2 9.2C, Yanmar 2Q15 engine. When I sail down wind, engine off and in neutral,I hear slightly knocking sounds from the transmission area. Looking at it no problem is visible. If I shift to Forward the noise goes away. I figure it is not detrimental to the transmission to stay engaged in gear with engine off while I am sailing. Any advice will be appreciated
Knocking sounds when sailing down wind
- Thread starter Avi
- Start date
Likely the shaft is turning from prop drag when in neutral... Check your manual, though.. Yanmar tends to not recommend putting transmission in reverse, and others definitely say NOT to put transmission in FWD under sail.
Do you have a folding prop? The knocking might indicate it needs service (sloppy blades). Alternately there IS a transmission issue that stops making noise when you lock it up.
Do you have a folding prop? The knocking might indicate it needs service (sloppy blades). Alternately there IS a transmission issue that stops making noise when you lock it up.
I would guess it makes the sound all of the time when sailing, but it is easier to hear when running down wind. You might want to check it (use AP or get someone to helm for you) and go below and look at your shaft, tranny, stuffing box, etc.
I believe Yanmar recommends shifting into REV if you want to lock the shaft while sailing.
I let mine free spin.
Greg
I believe Yanmar recommends shifting into REV if you want to lock the shaft while sailing.
I let mine free spin.
Greg
Pretty sure that Yanmar/Kanzaki combo says NOT to put in reverse, but to free wheel. Hurth/Zurn say to lock in REV but not FWD. However I suspect many yanmar users do shift to rev while sailing....
Yes, I think you are right. They changed the recommendation. I tried reverse one time, and I had a hard time shifting out of reverse and back to neutral.
Now I free wheel
Greg
Follow Yanmar's recommendations which are sail in Neutral as the transmission is in constant lubrication as the prop turns the shaft. My exception would be if there is mechanical factor in the running gear which is causing a vibration or non-normal noise in which case I would place it in Reverse. Check the motor mounts, the prop shaft, the cutlass bearing, propeller and obviously the transmission. Do not place the transmission in forward as it will place undue wear on the clutch. When using reverse to stop the shaft from turning you must slow the boat to under one knot before shifting to Neutral to avoid stress on the linkage and internals of the transmission.