THE FUEL SYSTEM AND GOVERNOR
31
To replace the primer:
4. If the primer is bad, disconnect hose from the
carburetor.
5. Remove the hose camp at the rear of the primer
bulb.
See Figure 4.13.
6. The primer is held to the shroud by a pair of split,
barbed posts. Squeeze the posts to release the
barbs.
See Figure 4.13.
NOTE: The primer bulb and hose will slide out
as an assembly.
7. Install the new primer by following the above
steps in reverse order.
Carburetors
If diagnosis indicates a fuel problem, inspect the carbu-
retor. This is important even if problems are identified
elsewhere in the fuel system..
IMPORTANT: the fuel must be tested for alcohol
content before diagnosing anything else on the
engine.
NOTE: It is important to perform a compression
or leak down test before condemning a carbure
-
tor. An engine can have a borderline compres-
sion reading and not create enough of a vacuum
to draw in a sufficient fuel/air charge.
NOTE: If the engine has border-line compres-
sion, a quick test to see if that is the problem is
to remove the spark plug. Squirt a little bit of oil
into the combustion chamber to seal the rings.
Reinstall the spark plug. If the engine starts and
runs ok, then that was the problem. If it does not
start, move on to the carburetor.
Inspecting the carburetor:
1. Remove the float bowl and check for dirt and/or
varnish.
2. Inspect the needle valve and needle valve seat
for dirt and/or damage.
3. Inspect the gaskets and O-rings for damage.
4. Inspect the vents and orifices, verify that they
are free of debris.
NOTE: If a little cleaning and new gaskets will fix
the carburetor, do it. If the carburetor requires
extensive cleaning it is better to replace the car
-
buretor.
IMPORTANT: Never try to mechanically clean
orifices. That will damage them and ruin the car
-
buretor.
NOTE: The jet markings (if present) may be
used for identification purposes, but the techni
-
cian should not attempt to infer orifice sizes from
the identification numbers.
NOTE: Installing the wrong main jet, or a carbu-
retor with the wrong main jet will produce perfor-
mance and emissions issues.
Figure 4.13
Clamp
Tabs
www.mymowerparts.com
For Discount White Outdoor Parts Call 606-678-9623 or 606-561-4983
To Next Page
Loading...
Need help?
General
