dumb impeller question

Posted by fgljff (fgljff@…>)

I pulled the impeller from the raw water pump on a Yanmar 1GM, but neglected to
notice the
direction of the veins. Does anyone happen to know, offhand, the direction the
veins should
point?

Posted by Dave_Benjamin (dave_benjamin@…>)

One article I read on that very topic mentioned that it doesn’t matter
which way you install it. The material will allow the veins to properly
orient themselves.

Alternatively you could give the starter a bump with the kill knob in
the engine off position. Look and see which way it turns.

— In freedomyachts2003@yahoogroups.com, “fgljff” <fgljff@…> wrote:

I pulled the impeller from the raw water pump on a Yanmar 1GM, but
neglected to notice the
direction of the veins. Does anyone happen to know, offhand, the
direction the veins should
point?

Posted by James Driebeek (jim3bk@…>)

The impeller shaft turns counterclockwise thus the veins will be
pointing clockwise. You can pre orient the veins in a tie wrap used
backwards, set to the same diameter as the housing. Align the
impeller with the flat on shaft and push the impeller out of the tie
wrap on to the shaft. If you are not running the engine any more
till next spring, you might want to keep the impeller out. I read it
is better for the rubber to be in a free state. When you do
reassemble your pump make sure your cover is free of grooves, use a
new gasket and maybe even new screws. The slightest leak will cause
a lot of frustration down the road. (It did for me).
As for my strainer, I took the whole thing apart to give it a
thorough cleaning and will re assemble it next year. I just blew out
the hoses with lung power.



— In freedomyachts2003@yahoogroups.com, “fgljff” <fgljff@…>
wrote:

I pulled the impeller from the raw water pump on a Yanmar 1GM, but
neglected to notice the
direction of the veins. Does anyone happen to know, offhand, the
direction the veins should
point?

Posted by William A. Cormack (wacormack@…>)

That’s right. The vanes will re-orient themselves.

A mechanic gave me a tip that I have followed annually since then. He said “replace the raw water impeller every year, the small cost of the part is well worth not overheating when one fails leaving you without power at an inopportune moment and possibly having to remove broken vanes from your heat exchanger.”

Leaving the new one out over the winter is a good idea too, so the vanes don’t “take a set” and become less effective.

Bill

----- Original Message -----
From: Dave_Benjamin
To: freedomyachts2003@yahoogroups.com
Sent: 12/07/2006 11:17 PM
Subject: [freedomyachts2003] Re: dumb impeller question


One article I read on that very topic mentioned that it doesn’t matter which way you install it. The material will allow the veins to properly orient themselves. Alternatively you could give the starter a bump with the kill knob in the engine off position. Look and see which way it turns.— In freedomyachts2003@yahoogroups.com, “fgljff” <fgljff@…> wrote:>> I pulled the impeller from the raw water pump on a Yanmar 1GM, but neglected to notice the > direction of the veins. Does anyone happen to know, offhand, the direction the veins should > point?>

Posted by Dave_Benjamin (dave_benjamin@…>)

William,
I don’t have much experience dealing with cold weather but I just
relaunched our Ranger 33 after being on the hard for a few months. I
was quite concerned after starting the engine since the water
discharge seemed much less than normal. I motored around a bit to see
if the temp would go up higher than normal but it didn’t.
The following morning it was back to normal. I’m guessing the cold
weather must shrink the vanes or otherwise cause it to lose
efficiency.


— In freedomyachts2003@yahoogroups.com, “William A. Cormack”
<wacormack@…> wrote:

That’s right. The vanes will re-orient themselves.

A mechanic gave me a tip that I have followed annually since then.
He said “replace the raw water impeller every year, the small cost of
the part is well worth not overheating when one fails leaving you
without power at an inopportune moment and possibly having to remove
broken vanes from your heat exchanger.”

Leaving the new one out over the winter is a good idea too, so the
vanes don’t “take a set” and become less effective.

Bill
----- Original Message -----
From: Dave_Benjamin
To: freedomyachts2003@yahoogroups.com
Sent: 12/07/2006 11:17 PM
Subject: [freedomyachts2003] Re: dumb impeller question

One article I read on that very topic mentioned that it doesn’t
matter
which way you install it. The material will allow the veins to
properly
orient themselves.

Alternatively you could give the starter a bump with the kill
knob in
the engine off position. Look and see which way it turns.

— In freedomyachts2003@yahoogroups.com, “fgljff” <fgljff@>
wrote:

I pulled the impeller from the raw water pump on a Yanmar 1GM,
but
neglected to notice the
direction of the veins. Does anyone happen to know, offhand,
the
direction the veins should
point?

Posted by crwindy@…> (crwindy@…>)

TIP:
I learned last year that it is MUCH easier to pull out the water pump and
replace the impeller with the pump out than it is to replace the impeller with
the pump ‘facing’ backwards.
cw
---- “William A. Cormack” <wacormack@…> wrote:

That’s right. The vanes will re-orient themselves.

A mechanic gave me a tip that I have followed annually since then. He said
“replace the raw water impeller every year, the small cost of the part is well
worth not overheating when one fails leaving you without power at an inopportune
moment and possibly having to remove broken vanes from your heat exchanger.”

Leaving the new one out over the winter is a good idea too, so the vanes don’t
“take a set” and become less effective.

Bill
----- Original Message -----
From: Dave_Benjamin
To: freedomyachts2003@yahoogroups.com
Sent: 12/07/2006 11:17 PM
Subject: [freedomyachts2003] Re: dumb impeller question

One article I read on that very topic mentioned that it doesn’t matter
which way you install it. The material will allow the veins to properly
orient themselves.

Alternatively you could give the starter a bump with the kill knob in
the engine off position. Look and see which way it turns.

— In freedomyachts2003@yahoogroups.com, “fgljff” <fgljff@…> wrote:

I pulled the impeller from the raw water pump on a Yanmar 1GM, but
neglected to notice the
direction of the veins. Does anyone happen to know, offhand, the
direction the veins should
point?

Posted by James Driebeek (jim3bk@…>)

this tip holds true for all Yanmars with external belt driven pumps,
not for the GM10


— In freedomyachts2003@yahoogroups.com, <crwindy@…> wrote:

TIP:
I learned last year that it is MUCH easier to pull out the water
pump and replace the impeller with the pump out than it is to
replace the impeller with the pump ‘facing’ backwards.
cw
---- “William A. Cormack” <wacormack@…> wrote:

That’s right. The vanes will re-orient themselves.

A mechanic gave me a tip that I have followed annually since then.
He said “replace the raw water impeller every year, the small cost of
the part is well worth not overheating when one fails leaving you
without power at an inopportune moment and possibly having to remove
broken vanes from your heat exchanger.”

Leaving the new one out over the winter is a good idea too, so the
vanes don’t “take a set” and become less effective.

Bill
----- Original Message -----
From: Dave_Benjamin
To: freedomyachts2003@yahoogroups.com
Sent: 12/07/2006 11:17 PM
Subject: [freedomyachts2003] Re: dumb impeller question

One article I read on that very topic mentioned that it doesn’t
matter
which way you install it. The material will allow the veins to
properly
orient themselves.

Alternatively you could give the starter a bump with the kill
knob in
the engine off position. Look and see which way it turns.

— In freedomyachts2003@yahoogroups.com, “fgljff” <fgljff@> wrote:

I pulled the impeller from the raw water pump on a Yanmar 1GM,
but
neglected to notice the
direction of the veins. Does anyone happen to know, offhand, the
direction the veins should
point?

Posted by andre laviolette (andrelaviolette@…>)
The vanes stiffen up in the cold. Takes a bit for them to get back their flex. Best to remove the impeler if engine mothbaled for several months. That said, I have never bothered and never had a problem in 32 years and 7 inboard boats. I, however, ALWAYS check water flow at exhaust outlet every time the engine is started ! I also change the impeller every couple of seasons and always carry a spare.Dave_Benjamin <dave_benjamin@…> wrote: William,I don’t have much experience dealing
with cold weather but I just relaunched our Ranger 33 after being on the hard for a few months. I was quite concerned after starting the engine since the water discharge seemed much less than normal. I motored around a bit to see if the temp would go up higher than normal but it didn’t. The following morning it was back to normal. I’m guessing the cold weather must shrink the vanes or otherwise cause it to lose efficiency.— In freedomyachts2003@yahoogroups.com, “William A. Cormack” <wacormack@…> wrote:>> That’s right. The vanes will re-orient themselves.> > A mechanic gave me a tip that I have followed annually since then. He said “replace the raw water impeller every year, the small cost of the part is well worth not overheating when one fails leaving you without power at an inopportune moment and possibly having
to remove broken vanes from your heat exchanger.”> > Leaving the new one out over the winter is a good idea too, so the vanes don’t “take a set” and become less effective.> > Bill> ----- Original Message ----- > From: Dave_Benjamin > To: freedomyachts2003@yahoogroups.com > Sent: 12/07/2006 11:17 PM> Subject: [freedomyachts2003] Re: dumb impeller question> > > One article I read on that very topic mentioned that it doesn’t matter > which way you install it. The material will allow the veins to properly > orient themselves. > > Alternatively you could give the starter a bump with the kill knob in > the engine off position. Look and see which way it turns.> > — In freedomyachts2003@yahoogroups.com, “fgljff” <fgljff@> wrote:> >> > I pulled the impeller from the raw water pump on a Yanmar 1GM, but > neglected to notice the > > direction of the veins. Does anyone happen to know, offhand, the > direction the veins should > > point?> >>
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Posted by katorpus (katorpus@…>)

— In freedomyachts2003@yahoogroups.com, “fgljff” <fgljff@…> wrote:

I pulled the impeller from the raw water pump on a Yanmar 1GM, but
neglected to notice the
direction of the veins. Does anyone happen to know, offhand, the
direction the veins should
point?

The fastest way to get an answer to this question for ANY engine is
to do the following…(takes two people)

  1. Pull the kill switch on the engine so it won’t start.

  2. Have your helper “bump” the starter switch while you watch which
    way things rotate.

It won’t matter that the lid is off the water pump and that the
impeller is not in place.

Use a permanent marker or paint pen to draw an arrow of the direction
of rotation on something permanent (like a belt pulley)…so you
won’t have to do this again.

Alternatively, think about which way the “prop walk” moves your boat.
If you have a right-hand propeller (turns clockwise when viewed from
the rear), it will “walk” the stern to PORT in reverse (and to
starboard in forward, although the latter is not nearly so pronounced)

If you can figure out which way your engine is turning, you will be
able to figure out which way the impeller is supposed to be placed,
but in reality, a NEW impeller can be installed into a CLEAN-BORED
water pump BACKWARDS and it will reorient itself as soon as the
engine is started without damage. If the boat’s been sitting up a
while and there’s calcification in the bore of the water pump, you’re
gonna wanna clean that out before you install the impeller ANYWAY, so
as not to eat up the blades grinding down the stuff that’s built up
in there.

“In theory, there’s no difference between theory and practice…In
practice, there is”

Posted by jerry weinraub (zayde@…>)

Makes no difference- When you start up,it will set itself. Do not assemble until ready to start,or the vanes may take a set

----- Original Message -----
From: katorpus
To: freedomyachts2003@yahoogroups.com
Sent: Sunday, February 11, 2007 12:29 PM
Subject: [freedomyachts2003] Re: dumb impeller question


— In freedomyachts2003@yahoogroups.com, “fgljff” <fgljff@…> wrote:>> I pulled the impeller from the raw water pump on a Yanmar 1GM, but neglected to notice the > direction of the veins. Does anyone happen to know, offhand, the direction the veins should > point?>The fastest way to get an answer to this question for ANY engine is to do the following…(takes two people)1) Pull the kill switch on the engine so it won’t start.2) Have your helper “bump” the starter switch while you watch which way things rotate.It won’t matter that the lid is off the water pump and that the impeller is not in place.Use a permanent marker or paint pen to draw an arrow of the direction of rotation on something permanent (like a belt pulley)…so you won’t have to do this again.Alternatively, think about which way the “prop walk” moves your boat. If you have a right-hand propeller (turns clockwise when viewed from the rear), it will “walk” the stern to PORT in reverse (and to starboard in forward, although the latter is not nearly so pronounced)If you can figure out which way your engine is turning, you will be able to figure out which way the impeller is supposed to be placed, but in reality, a NEW impeller can be installed into a CLEAN-BORED water pump BACKWARDS and it will reorient itself as soon as the engine is started without damage. If the boat’s been sitting up a while and there’s calcification in the bore of the water pump, you’re gonna wanna clean that out before you install the impeller ANYWAY, so as not to eat up the blades grinding down the stuff that’s built up in there. “In theory, there’s no difference between theory and practice…In practice, there is”