Service manual

REV C 5-2 115615
6. Never operate the machine without an air filter installed.
Overservicing
Overservicing occurs when an air filter element is removed
for cleaning or replacement before it is necessary. Each time the
filter is removed a small amount of dirt and dust could fall in the
intake system. This accumulated dirt can cause a dusted engine.
It only takes a few grams of ingested dirt over the normal
service life of an engine to cause a dusted engine.
Do not clean the element, but replace with a new element
only. Cleaning used air filter elements, through improper
cleaning procedures, can get dust on the inside of the filter
causing dirt ingestion and engine failure.
It is important to note that whenever an air filter element is
cleaned by any method, the person or company performing the
cleaning assumes responsibility for the integrity of the filter
from then on. The warranty for air filters expires upon
cleaning or servicing in any manner because the condition of
the filter after servicing is completely out of the filter’s
control. Therefore, on a dust ingested engine failure, there
will be no warranty consideration if the air filter element
has been cleaned or serviced in any manner.
A partially dirty air filter element works better than a new
element. Therefore, a dirty filter element is not bad for the
engine unless it is excessively restricting the air flow and engine
performance is affected. The reason is simple. The media in the
filter must be porous to allow air to pass through it. When dirty
air passes through the filter, the dirt plugs some of the holes in
the media and actually acts as part of the filter media. When the
next round of dirt enters, the first dirt helps filter out even
smaller particles making the filter more efficient at stopping dirt
from entering the engine. This is referred to as barrier filtration.
Of course, at some point the filter media becomes too clogged
to allow air to pass.
The mowing conditions will determine the frequency of air
filter element changing.
Fuel Evaporation System Filter
All BigDog
®
X Diablo mowers with a 9xxxxx (i.e. 922222)
model number, have a fuel evaporation system filter. Refer to
the following table for more detailed information. Figure 5-4
BigDog
®
X Diablo mowers with a 9xxxxxAU or 9xxxxxEX
(i.e. 922222AU or 922222EX) model number may or may not
have a fuel evaporation system filter. Refer to the following
table for more detailed information. Figure 5-4
This filter must be replaced every 500 hours or annually
whichever comes first.Figure 5-4
Fuel & Evaporative System Line Routings
Domestic mowers
There are two rubber hoses that are connected to the fuel
tanks. One is the fuel hose that is part of the fuel system. The
other is the vapor line that is part of the fuel evaporative system.
On mowers produced prior to s/n 12080000 the fuel hose is
connected to the port on the side wall of the fuel tank. It
connects the fuel tank to the fuel shutoff valve. Figure 5-5
On mowers produced after s/n 12080000 the fuel hose is
connected to the rear port on the fuel tank. It connects the fuel
tank to the fuel shutoff valve. Figure 5-6
On mowers produced prior to s/n 12080000 the vapor line
is connected to the port in the top of the fuel tank. It connects
the fuel tank to the engine’s vapor port. Figure 5-7
Figure 5-3
Safety filter
MODEL
EXTENSION
MODEL
EXAMPLE
SERIAL NUMBERS
NONE 922222 ALL HAVE FILTER
EX 922222EX PRIOR TO SERIAL NUMBER
12100000 HAVE FILTER
AFTER SERIAL NUMBER 12100000
DO NOT HAVE FILTER
AU 922222AU PRIOR TO SERIAL NUMBER
12100000 HAVE FILTER
AFTER SERIAL NUMBER 12100000
DO NOT HAVE FILTER
Figure 5-4
Fuel evaporation
system filter