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Eastward ho 24 · 03-10-2016, 14:31

Hello every one...question... While undersail I usually keep my 1977 md7a in neutral. Once I'm up around 5 knots I hear the prop "whirling". I assume in neutral this eliminates the transmission gears from turning since the motors not running no lube or cooling..I've googled a little found some people put it in reverse. I have a fixed three blade prop and was wondering what the correct procedure is.. Thanks

Sandero · 03-10-2016, 14:39

I think Volvo says IN gear.

Sailmonkey · 03-10-2016, 14:40

Surely they say in reverse gear, i.e. Opposite the direction of travel.

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Eastward ho 24 · 03-10-2016, 15:34

Hmm reverse gear is a sureity? It's a left hand prop if that has any bearing on it

**tkeithlu** · 03-10-2016, 15:38

Whatever the detail, you do not want the shaft turning while the engine is off. That will damage your transmission, and possibly your Cutless bearing/shaft seal as well. For awhile, there was a shaft lock on the market that held the shaft with a detent that could be overridden, at the cost of an unholy noise, if you engaged the motor/transmission without pulling the spring-loaded detent plunger out of the way.

Eastward ho 24 · 03-10-2016, 16:20

I don't have a shaft lock.. Gonna have to look into it. In the mean time. How do I eliminate cutlass and tranny damage?

Sailmonkey · 03-10-2016, 16:29

Quote:

Originally Posted by Eastward ho 24

Hmm reverse gear is a sureity? It's a left hand prop if that has any bearing on it

manualslib

Download Contents
Volvo Penta MD7A Instruction Book Page 11
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RUNNING INSTRUCTIONSFolding propeller, S-drive. When switching from engineoperated running to sailing the propeller rotation is stopped byengaging reverse gear. When sailing maintain the controllever in the reverse position.Fixed propeller. When sailing the control lever should be inthe neutral or reverse position. During long sailing trps withthe lever in the neutral position, the engine should be run forsome time every tenth hour in order to ensure lubrication inthe drive or reverse gear.Switch off the main switch. NOTE! The main switch mustnever be switched off until the engine has stopped completely(the charging regulator can be damaged).Close the fuel and cooling water cocks if the boat is not goingto be used for some time.Check for leakage before leaving the beat.In cold weather and whenever there is a risk of temperaturesbelow zero, the cooling water must be drained from the engineand the reverse gear. Close the cock on the cooling waterintake, (S-drive model 110S: See page 19). Close all thedrainage cocks if the boat is left without regular supervision.An incorrectly performed draining can result in a sunken boat.(See positions 15 and 16, page 34).7
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Sailmonkey · 03-10-2016, 16:30

Straight from the Volvo manual that I found online with about a minute of digging.

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Eastward ho 24 · 03-10-2016, 16:41

Well thank you very much guess I used the wrong keywords in my search. "Run the engine every tenth hour doesn't seem very efficient. Guess it's a folding prop or the shaft lock. If I was in gear under sail and the prop was turning would that mean the pistons are moving aswell and the oil pump pumping etc? Where would the fuel pump come into play,? Obviously my logic must be flawed here.I was thinking isn't the oil pump mechanical therefore wouldn't it be lubricating the motor.

**StuM** · 03-10-2016, 17:09

Quote:

Originally Posted by Eastward ho 24

"Run the engine every tenth hour doesn't seem very efficient.

It's a trade off. "Fixed propeller. When sailing the control lever should be inthe neutral or reverse position. During long sailing trps withthe lever in the neutral position, the engine should be run forsome time every tenth hour in order to ensure lubrication inthe drive or reverse gear."

Lever in neutral - less drag, sail faster, but you need to periodically run the engine to maintain lubrication.
Lever in reverse - more drag, sail slower, but no need to worry about lubrication.

Quote:

If I was in gear under sail and the prop was turning would that mean the pistons are moving aswell and the oil pump pumping etc?

If you're in gear and the prop is turning, you've got a bl**dy fast boat. As a WAG, you'd need to be doing several times your hull speed.

Eastward ho 24 · 03-10-2016, 17:25

Ok thanks when I hit 5 knots I hear her turning and that's not often haha, while I got your ear..was wondering your 2 cents on dripless shaft seals and feathering props...I plan on taking this little boat on an offshore voyage And I'm trying to prepare for it haven't gotten into drive train yet ( working on my rigging as I wait for "riggers apprentice" in the mail. Don't know much, but what I do know is I hate water dripping from my shaft seal, the boats a very dry boat otherwise. I hear if a dripless seal fails it's usually catastrophic? If I were to be in say South America or remote places what would you think is best ? Once again thank you

DougR · 03-10-2016, 18:01

With a fixed propeller, if you allow the transmission to remain in neutral, the prop shaft and the gears within the reduction housing on the rear of the transmission will continue to rotate, and this is part of the noise that you hear. The manual recommends that you run the engine periodically to lubricate and cool these gears and the transmission oil.

If you place the transmission in reverse gear, nothing will rotate and there is no need to run the engine periodically, as there is no heat generated. However, there will be a bit more drag and you will sail somewhat slower.

DougR

Sailmonkey · 03-10-2016, 18:10

Like stu said, if the prop is turning, the engine will need to be started every ten hours. Put the transmission in reverse and you will not need to start the engine. Nor will the engine turn. Nor will anything need lube.

As far as dripless seals, I've got one and it failing, imho would not be catastrophic. If the bellows tears (uncommon) tape has been known to fix it. If another part fails, lock the prop wrap something around the shaft and go somewhere to fix it.

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