HydraMaster Boxxer 421, Owner'S Manual

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HydraMaster Corporation
Page 10-4: Engine Troubleshooting
Boxxer 421
6.5. Inadequate fuel supply to the carburetor . Test the fuel volume at the carburetor by
removing the fuel line from the carburetor inlet and placing the line in a metal container with
a minimum of 16 oz capacity. Turn on the ignition switch to operate the fuel pump. The
fuel flow volume should be 12 oz / minute. Check for clogged filter or obstructed fuel line.
Also check to make sure the fuel pump is mounted vertically and is close to the fuel
source. Repair as necessary.
7.0.Runs rich (Black smoke)
7.1 . Dirty air filter . Inspect and replace as necessary.
7.2. Choke is partially closed. Inspect and adjust or repair as necessary.
7.3. Excessive fuel to carburetor . Insure that fuel pump is proper PSI rating. A fuel pump
with a psi rating in excess of that of the pump supplied with the machine could overpower
the inlet valve in the carburetor, causing excessive fuel to be supplied to the carburetor.
8.0.Engine overheats
8.1. Poor ventilation in vehicle . All cargo area doors must be open for proper ventilation.
Roof vents are strongly recommended for machines that are operated in hot climates. Any
item that might restrict air flow to the machine such as other equipment or a solid divider
should be moved or modified to permit proper air flow.
8.2. Low engine oil level . Check oil level and replenish as necessary.
8.3. Engine RPM too high . Check RPM with an accurate tachometer. Adjust as necessary
to 3000 RPM.
8.4 . Restricted engine or blower exhaust . Disassemble exhaust components to locate
restriction. Repair as necessary.