Noise below cockpit while sailing

[Michael Shaner]

Juan...in light of the PYI, have you "burped" it lately? Could be some air in here...sometimes I get more vibration than others...burping seems to help...

But I'm still gonna' get to dialing in my alignment...sometime...I know I'm closer to it than I've ever been...I swear it...

[Roc]

OK, since you do have the PYI seal.  Here's what you might want to check.  I noticed with mine, the carbon section would jump/vibrate, as the shaft is turning, making a loud knocking sound.  Sounded like someone was hitting the shaft with a hammer.  At the time, I had the unit hooked up to my exhaust, where water would flow into it to cool it (it's the 'high speed unit').  Since then, I changed it by removing the direct injection of water, to running a hose from the nipple to a spot high above the water line.  This is now how PYI suggest it be mounted, and I believe they don't sell the unit without the water cooling injection port anymore (the 'low speed unit').  No problems with the tapping noise anymore.

[Meerkata]

Noise is probably caused by turning prop. 35B manual says no need to put engine in gear, but it does stop shaft from turning while under sail.
Hint, you can look at shaft (aft of engine) under aft birth to see if it is rotating when you hear the noise.
Also, if you sail with a spinacker, you definately will want the engine stopped, else you will sooner or later wrap the lazysheet onto the shaft.
Jim-of-Meerkat

[Stu Jackson]

35B manual says no need to put engine in gear,

Just a reminder:  the engine manual is NOT the transmission manual.  Neutral or, preferred in reverse.  NEVER in forward for Hurth transmissions.

[Jack Hutteball]

As I have posted before, the noise could be from a loose shaft zinc that has slid down and rattling against the strut.  You won't hear it when motoring.  Has happened to me and others.

Jack