Nate Nagel wrote:

On 07/21/2010 09:07 PM, The Daring Dufas wrote:
On 7/21/2010 7:12 PM, Smarty wrote:
I personally installed a Generac natural gas stand-by generator 5
years ago, after a freak October ice storm knocked out
electricity in this area for nearly 2 weeks.

The Generac has worked flawlessly over the last 5 years,
including the weekly exercise it does to ensure integrity, except
for one HUGE problem:

Every year or so, a $5 rubber part which Generac calls a "bellows"
ruptures without warning, leaving the generator totally unable to
start / run.

This rubber bellows is nothing more than 2 inch long corrugated
and flexible connector which provides a flexible hose connection
between the carburettor air input and the air filter's air
output. Once it ruptures, the air/fuel ratio is grossly changed,
and the engine will neither start nor run. The rupture is not
especially visible, and only has to be the size of a pin-prick to
spoil the mixture and prevent combustion.

Generac uses a flexible coupling of this type to absorb vibration
which the engine and attached carburettor create, and dissipate
it and isolate it from the separately mounted and isolated air
filter, which sits in an adjacent chamber next to the engine.

No doubt the heat and vibration of the engine do a real job on
this rubber part, and I have been replacing them as they fail,
only to have the replacement fail less than a year later.

I spoke with Genrerac's local parts distributor, and then with a
factory Generac parts manager, hoping to find a replacement part
with a better life expectancy. When the first one failed during
the warranty period in the 10th month, I was told by the Generac
service technician that this was a common problem, and that
Generac has issued a newer and better bellows to fix the problem.
He assured me that I would NOT see this happen again.

He lied, or was ill-informed...... I am now on my 4th one, and
was told today by Generac that there are no new or replacement
alternatives they are aware of.

The one and the only part they sell to do this job can be seen at:

http://www.gasoutdoor.com/details.asp?id=19775



Now that those of you with the patience to read this far know and
understand my predicament, I am posting here with the following
questions:

1. Are there any high-temperature hose materials which can
withstand the engine compartment temperatures and vibration which
I might use instead, which would allow me merely to make a direct
2" long connection? The ID of the hose is 1.5", and should be a
pretty standard, easy-to-find size.

2. If I use a replacement coupler which has the flexibility of a
"bellows" to allow it to dissipate vibration in the same manner
as the current part, are there other flexible couplers which
exist which would allow a more permanent / durable connection?

3. If there are no superior parts to be purchased because options
1 or 2 above do not exist, is there a 3rd option to treat this
rubber bellows in some manner to strengthen it and make it far
less vulnerable to heat and vibration?

Presumably somebody must make a flexible coupler for 1.5" diameter
connections which can take the heat and vibration better than
this $5 rubber part.

To avoid digressions, I want to point out here at the onset that
the Generac is otherwise working properly, the engine is not
vibrating excessively, the temperatures are not rising
excessively, and the usage is extremely light, nearly all of it
being the weekly check-out self-test. Unfortunately 10 months of
self-test seems to be enough to destroy this part. I am very much
aware that replacing this part on a preventative maintenance
schedule every (let's say) 9 months would quite possibly solve
the problem, but I am really not interested in doing so if there
is some reasonable alternative, even if the part cost is much,
much higher.

I am open to any ideas and suggestions, and much appreciate your
time in reading this, and possibly replying. Thank you very much.


I install a bunch of the older 8kw units that had the Vanguard
engine, yours must have the newer Generac manufactured engine. Have
you ever seen the silicone radiator hoses installed on taxi and
police car engines? You might ask an old wrinkled up parts counter
man at a real auto parts supply house if he can find one for you.

http://www.siliconestop.com/

TDD


They're also sold for custom air intakes for ricers for that matter,
and that might be the best idea I've heard yet.

http://www.pegasusautoracing.com/gro...upID=TURBOHOSE

something like a "hump hose" is probably what you want, for better
vibration isolation. I don't see them that small on Pegasus' site,
but I did get a couple hits when I searched online, just nothing from
a brand I recognized. For $20 or so, it's worth a try. Just use a
lined hose clamp at each end; silicone hoses don't like the "teeth"
on typical worm drive hose clamps, it tears 'em up.

Pegasus does sell lengths of straight coolant hose in all sorts of
sizes, so that's an option too.

nate

Thanks Nate and will definitely get lined clamps. Never knew there was
such a think until I read your reply and did some Google searching! Of
course I would have used the wrong type which apparently extrude the
silicone of the hose........