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
Every year or so, a $5 rubber part which Generac calls a "bellows"
ruptures without warning, leaving the generator totally unable to start
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
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:
Now that those of you with the patience to read this far know and
understand my predicament, I am posting here with the following
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
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.