HydraMaster Boxxer 423s, Owner'S Manual

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8-7: Systems Troubleshooting Systems Troubleshooting: 8-6
7.0 Engine overheats
Possible Cause Solution
7.1 Poor ventilation in the van. Open all the van doors.
Install a roof vent in the van.
Remove any dividers or other objects impeding airflow
around the truckmount.
7.2 Low oil level.
Check the level and fill as necessary.
Running the engine with a low oil level can
cause severe damage to the engine. If
this situation occurs, the engine should be
inspected by a qualified service technician.
7.3 The engine rpm is too
high.
Check the engine rpm. Adjust as necessary to run at
3,200 rpm under no vacuum load.
7.4 Excessive back pressure
on the engine exhaust.
Inspect for blockage in the heat exchanger. Clean or
replace as necessary.
4.0 Will not come up to normal operating rpm. Note: engine should be adjusted to
run at 3,200 rpm under no vacuum load.
Possible Cause Solution
4.1 The throttle linkage is out
of adjustment.
Inspect for broken or loose linkage. Repair or replace
as necessary.
4.2 Excessive load on the
engine.
Inspect and clean the recovery tank filters.
Inspect the recovery tank to the blower hose. Repair
or replace as necessary.
4.3 Excessive back pressure
on the engine exhaust.
Inspect for blockage in the heat exchanger. Clean or
replace as necessary.
4.4
The air filter is dirty.
Inspect and replace as necessary.
5.0 Runs rough at high speed
Possible Cause Solution
5.1 The spark plug(s) are
faulty.
Remove and inspect the plugs. Clean or replace as
necessary.
5.2 The spark plug wire(s) are
faulty.
Inspect the wires and connectors for damage or
loose connections. Repair or replace as necessary.
5.3 Inadequate fuel supply to
the carburetor.
Check if the fuel pump is mounted in a vertical
position near the fuel source. Correct if necessary.
Check for blockage in the filter. Repair or replace as
necessary.
If operating altitudes have changed, contact your
distributor to have the engine carburetor jets
checked.
6.0 Runs rich. (Black smoke)
Possible Cause Solution
6.1
The air filter is dirty.
Inspect and replace as necessary.
6.2 The choke is partially
closed.
Inspect and adjust or repair as necessary.
6.3 Excessive fuel to the
carburetor.
Check to see if the proper fuel pump is installed.
If operating altitudes have changed, contact your
distributor to have the engine carburetor jets
checked.