While Sailing: Forward or Neutral Gear?

[rpowers]

Ok, here's the problem.

Last two times out sailing we were really jamming, full tilt heel, max speed, surfing down waves, etc.

My transmission was in forward gear the whole time.

When I went to start the engine to motor into the marina, No Start.

Found water in the cylinders and carb. The water was black with soot, as if from the exhaust passages.

Cleaned out the carb, dried the cylinders and plugs, and it starts right up.

I suspect that while sailing my prop was turning over the engine, slowly flooding it with water that was unable to escape with normal exhaust pressure pushing it out.

Questions:

1) Should I sail with the engine in neutral?

2) Will the free spinning prop shaft cause undo wear?

4) Or is is better to leave it in forward gear and close a (new to be installed) water valve between the through-hull and pump?

5) Or do I have some other weird problem?

Let's leave prop drag/sailing speed out of the equation for the purposes of this discussion.

Let the opinions fly!

-Rick

[Will Jacocks]

Maybe convert to a folding prop? That helps the speed too!

[hanleyclifford]

Install a thru hull shut off and close the thru hull while sailing. There is a remote possibility water is getting in thru the exhaust. Best not to sail with trans in neutral (no oil getting to bearings).

[mikke60]

Are you saying it is better to sail in gear? This is something I am not aware of.

[roadnsky]

Rick-
Question...

When you shut down to start sailing, do you shift to NEUTRAL before shutting down and then shift back into gear?
OR, do you just shut down at low RPM while still in forward gear?

[rheaton]

Do you have an anti syphon valve in your exhaust system. One is required on the water output host from engine into exhaust system.

[Al Schober]

Rick,
I have my engine in gear while sailing, and I've never had the prop turn the engine. I seriously doubt that's what's happening.
It sounds like water is getting in through your exhaust while sailing 'full tilt'. How high is your hot riser before the water injection? How about trying a plug in the exhaust? It wouldn't really have to seal tightly - just keep the stern wave from flooding your exhaust line. Put a string on the plug so you don't lose it if you start the engine with it in place.

Al

[sailhog]

I can't turn my prop shaft by hand when the tranny is in forward.

[Dave Neptune]

In gear!

Rick, I agree with Al. I doubt that the prop is turning the engine, I have a 3 blade and ALWAYS shut down to start sailing in gear and leave it there. A free spinning prop will create more drag due to surface friction while spinning. It's sort of like more "water area swept" than when locked in gear. It will also save wear and tear on any spinning parts in the drive line.
Check the anti syphon and look at your exhaust position. If it is under the transon and you are surfing down hill the action of the transom in the water will pump water back into the exhaust. Some boats are noted for this such as the E35-MkII like mine. When I am in a good down hill situation I shut off the valve at the transom, I just have to remember to open it back up when starting.

Dave Neptune

[rpowers]

Good answers!

Thanks all.

Engine is turned off while still in gear.

I do not have an anti-siphon valve on the hot water hose to the exhaust pipe.

Could someone show me what that looks like? Where to get?

My hot pipe riser goes to the bottom of the cockpit floor (max possible).

This morning I installed a water cut-off valve just before the water pump. The idea would be to close it before sailing, then (remember to!) open it before motoring in.

Maybe the suction out the back exhaust is pulling water in. What kind of plug/flapper can be used there?

And Dave N., what kind of valve do you have on the exhaust hose? My hose is about 2" diameter...

Thanks again all!

-Rick

[ndutton]

Really, the only way you can get water into the engine with a good running A-4 is in through the exhaust. With the engine off the water is getting there either from the transom or through the thru-hull and pump by way of the waterlift. I don't recall, did you determine the shaft was turning with the engine off and in gear?

I don't think it's through the engine although your new valve should guaranty that it's not. BTW, what some guys do to remember to open a critical valve such as your new one is to hang the ignition key on the valve handle.

Up through the exhaust is another matter. Extreme heel is likely a contributing factor. Have you considered reefing in such conditions? You might not be shipping water aboard, maybe what found its way into the engine was residual in the waterlift.

[dvd]

Rick

From the photo posted it looks like you have a Catalina 27? Anyway as you probably have noticed, when you are reallly going with the kite up the back end of the boat and transom sucks way down into the water. Now if you are doing this and you have several guys in the cockpit it is highly likely that udner this point of sail your exhaust is underwater. I had a cal 27 with an outboard and when we had the kite up with a coupla 3 guys in the cockpit working it the whole cockpit woild fill with water. I wouldn't suspect that the exhaust would under water when heeled to weather. I would bet that your problem arises while doing fast kite runs and that is when you are sucking up water.

dvd

[JOHN COOKSON]

My Vote

Your shaft should not turn if the engine is left in gear while sailing. Have you looked at the shaft while sailing in gear to verify this?

If the shaft is turning there is a possible problem somewhere - or your sparks are loose or out (just kidding).

Me thinks you have an exhaust system problem.

Your boat is a Catalina 30?

? for the forum: If the shaft did spin while sailing in forward gear would it turn the engine in forward rotarion or in reverse rotation?

TRUE GRIT

[rpowers]

More info

(The photo with Spinnaker was just for entertainment)

Both of these floods occurred without spinnaker.

When I get 2 or more people in my Cat27 cockpit, the stern drops and the exhaust is below the water line.

My exhaust lift pipe comes up to the floor height.

I agree with those who say the prop can't spin the engine.

It must be water coming up the exhaust pipe.

With the diagram below, where/what should I do?

-Rick

[sastanley]

Rick, Most of our Catalinas came with a little rubber flap on the transom exhaust fitting. Mine currently does not have one..it fell off when I was a kid.

Catalina Direct makes a nice stainless flapper fitting. However, I found that to replace the existing plastic thru-hull fitting for 1 5/8" hose (almost 2" diameter hole in the boat), I'd have to do some filling, as this requires a much smaller cut-out..I assume the walls are thinner since it is metal.

What you also need is an anti-siphon loop in that water hose connection..it needs to be as high as possible, hopefully above the water line at all angles of heel. Mount it as close to the center of the boat as possible..just under the cockpit floor maybe since you engine is under the steps. - Since my engine is mounted under the galley counter top in the middle of the boat, my anti-siphon loop is mounted right next to the sink, under the counter top.

Forespar makes them in marelon - the proper term is a "vented loop" - it breaks the siphon with its little vent in the cap when you turn off the motor..