Hi does anyone have problems with alternator belts breaking 2 or 3 times a
yr. about 100 hrs./yr. Looks to me the cause is rust on the pulleys grinding
down the belts and leaving a nasty rubber powder behind, I always keep a
spare on board never had to change out of port,(almost the last time out but
I thought my partner lost the anchor and I was close to port.) never had to
get towed yet thanks goodness. The pulleys look to be running true. I think
it is when I start it the first time for the day I have to pump the carb.
alittle, (throttle) and leave it open some and the jump in rpm's and first
rust of the day pops it off. What do u think? Thank u all, Need Help in
Jersey.

P.S. it is a 1993, 351, OMC King Cobra.

"Wildest Dream" wrote in message
. net...
Hi does anyone have problems with alternator belts breaking 2 or 3 times a
yr. about 100 hrs./yr. Looks to me the cause is rust on the pulleys
grinding
down the belts and leaving a nasty rubber powder behind, I always keep a
spare on board never had to change out of port,(almost the last time out
but
I thought my partner lost the anchor and I was close to port.) never had
to
get towed yet thanks goodness. The pulleys look to be running true. I
think
it is when I start it the first time for the day I have to pump the carb.
alittle, (throttle) and leave it open some and the jump in rpm's and first
rust of the day pops it off. What do u think? Thank u all, Need Help in
Jersey.

How's the tension. Properly adjusted?

Belt breaking is usually caused by misaligned pulleys or structurally weak
mountings that allow vibration. Both usually indicate a missing/bent/wrong type
bracket. If the pulleys have taken a bad set and worn side to side the belt can
be bottoming in the groove. That will cause them to wear out prematurely
because they slip.
First use a straight edge across the front edge to see if the pulleys look
right. Look for wear in the sides of the grooves. Then take a good listen at
idle speed with a new belt properly tensioned. Do you hear it popping and
scrubbing. Is there any strange resonance or vibration at various RPMs? Is it
running true, not wobbling ? I bet by then you will have seen the problem. The
toughest thing to find is a missing bracket since you may not be able to look
at one that is set up properly. Marine setups are sometimes cludged together
and they may have removed a bracket you would have in a car, to make room for
something else.

"Gould 0738" wrote in message
...
How's the tension. Properly adjusted?

It is the pulley's. My 351 was also going through belts. The 351 is a
marine engine from Ford and Red Line Marine in Lewiston, ID is a parts
distributor. The pulleys are only one the marine engine. Red Line ships,
the pulleys are not cheap. Pull the pulley's and check the numbers on them.
They are stamped in to the metal.
Bill

Calif Bill wrote:
"Gould 0738" wrote in message
...

How's the tension. Properly adjusted?


It is the pulley's. My 351 was also going through belts. The 351 is a
marine engine from Ford and Red Line Marine in Lewiston, ID is a parts
distributor. The pulleys are only one the marine engine. Red Line ships,
the pulleys are not cheap. Pull the pulley's and check the numbers on them.
They are stamped in to the metal.
Bill



All the above, but also be aware the harmonic balancer (crankshaft
pulley) can move out of alignment on it's rubber bush as they get older.

Particularly so if you accelerate the engine hard with no load, as you
describe.

Also just confirm all the pulleys are the same profile (usually "A").

Marine belts on "normal" pulleys seem to last OK if properly aligned &
tensioned, so the slight surface rust you describe is not unique to your
boat.

K


This is an example of liar Harry's MO, he pretends he has actual
experience than he can say whatever, he invents his jetski so he can
spread his lies & hate in the jetski NGs, till they told him to sod off.

As far as your other complaints, well, almost every president in my memory,
and I *remember* Truman, Eisenhower (who cheated on his wife), Kennedy,
Johnson, Nixon, Ford, Carter, Reagan and Bush, lied and participated in
deceit to one degree or another, and on issues far more important than who
was giving them blow jobs.

Good lord. I met *every* president in the damned group except Bush, and I
worked once for his father.

K Smith wrote:


This is an example of liar Harry's MO, he pretends he has actual
experience than he can say whatever, he invents his jetski so he can
spread his lies & hate in the jetski NGs, till they told him to sod off.

As far as your other complaints, well, almost every president in my memory,
and I *remember* Truman, Eisenhower (who cheated on his wife), Kennedy,
Johnson, Nixon, Ford, Carter, Reagan and Bush, lied and participated in
deceit to one degree or another, and on issues far more important than who
was giving them blow jobs.

Good lord. I met *every* president in the damned group except Bush, and I
worked once for his father.



So tell us, Karen of Oz, did you go to school to learn how to be an
idiot, or did it come naturally to you?

First use a straight edge across the front edge to see if the
pulleys look
right.

Won't work if the outside edges are different castings or pressings.
Better is to drop a dowel with a diameter of the belt width so it
doesn't touch the bottom of the groove. The dowel can be just barely
the length of a suspended leg of the belt so it's easy to get in
there. Take a look at how the dowel rests in the groove, using ink to
help if it's tough to get a lotta light and a dental mirror in there.
Do it at several positions of the pulleys. If it's not right on the
money you've got a problem.

What confuses me is I can't locate a carbon fiber/kevlar(?) toothed
belt (they run cooler) for my motor. It's a very short belt, from a 4"
to a 2.2" pulley. The ones I use are stretchy and require adjustment
during the belt's service life. I'd pay for one that didn't. I think
they're for lawnmovers or something. Is stretch a design consideration
in alternator belts? Sort of a high load slipping clutch like the
doughnuts in an outboard propellor?

"Calif Bill" wrote in message link.net...
"Gould 0738" wrote in message
...
How's the tension. Properly adjusted?

It is the pulley's. My 351 was also going through belts. The 351 is a
marine engine from Ford and Red Line Marine in Lewiston, ID is a parts
distributor. The pulleys are only one the marine engine. Red Line ships,
the pulleys are not cheap. Pull the pulley's and check the numbers on them.
They are stamped in to the metal.
Bill

Tell us, Bill, how are you 100% sure it's the pulleys, and all of
them? Could it not be just ONE pulley with a burr on it, or worn so
that it's not true anymore? Could it not be that one or more pulleys
are out of alignment with the others? Could it be that the harmonic
balancer is not aligned properly, thus allowing the crankshaft pulley
to run eccentric?

Like I said the pulleys don't look to be out of alignment, I will check with
straight edge, probably in winter storage. Belts on pulleys don't look to be
bottoming out all belts align up with pulleys I looked at that. Guess I
could look harder but pulleys don't appear to be worn. I also replaced the
power steering/waterpump belt when I first got the boat 2 yrs. ago, and it
is still working no problems with it. But this harmonic balancer u are
talking about K Smith, how can I check it? The part I think your talking
about is # 38 the damper crankshaft, is it
not(http://216.37.204.206/Actionsports/O...pe=13&A=48&B=4) .
Seems like the alt. belt has to be tighter than normal (but not so tight I
can't get a 1/4 inch deflection) if its very loose it will squeal, That
Damper is allot of money would like to know how to test it before I spend
$100, I didn't know it was there am used to automotive pulley on crankshaft
don't have one. Thanks for all your reply's I guess I will have to do some
investigation further, it stinks to have to change your belt on a day off
trying to go out to sea. Happy Boating


"Gene Kearns" wrote in message
...
On Tue, 07 Oct 2003 15:04:08 GMT, "Wildest Dream"
wrote:

Hi does anyone have problems with alternator belts breaking 2 or 3 times
a
yr. about 100 hrs./yr. Looks to me the cause is rust on the pulleys
grinding
down the belts and leaving a nasty rubber powder behind, I always keep a
spare on board never had to change out of port,(almost the last time out
but
I thought my partner lost the anchor and I was close to port.) never had
to
get towed yet thanks goodness. The pulleys look to be running true. I
think
it is when I start it the first time for the day I have to pump the carb.
alittle, (throttle) and leave it open some and the jump in rpm's and
first
rust of the day pops it off. What do u think? Thank u all, Need Help in
Jersey.


This is (very) excessive. Check alignment, fit for sheave to sheave
and belt to sheave(s), and proper tension. Use the manufacturer's
specs for setting all of the above. Beyond this might be an overload
caused by too great a pre load on alternator bearings or more esoteric
crap..... check the simple things first..... and report back....

--



Grady-White Gulfstream, out of Southport, NC.

http://myworkshop.idleplay.net/cavern/
Homepage
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