Mallory Ignition 5250, 5250A User Manual

1MALLORY IGNITION www.mrgasket.com

COMP PUMP®SERIES 250

ELECTRIC FUEL PUMP

PART NOS. 5250 AND 5250A

INSTALLATION INSTRUCTIONS

FORM 1038 (REV. F) 11/04

GENERAL INFORMATION

The COMP PUMP®250 Series Electric Fuel Pump is a high
volume fuel pump designed for serious racing applications.
The pump is factory set to approximately 15 PSI. In all
cases, this fuel pump must be used with a fuel pressure
regulator. We recommend the following:

Standard Regulator

Mallory 4 Port Regulator Part No. 4200 (gasoline)

Part No. 4201 (alcohol)

Return Style Regulator

Mallory 5 Port Regulator Part No. 4300M (gasoline)

Part No. 4301M (alcohol)

This fuel system must have a fuel return line going to the fuel
tank. We recommend at minimum a #8 AN (1/2") line.

If you use a standard fuel pressure regulator, not a return
style, run the fuel return line from the fuel pump’s fuel return
port. Use the 3/4"-16 thread x #8 AN flare fitting provided to
connect your #8 AN line.

If you use a return style fuel pressure regulator, run a #10 AN
fuel return line from the fuel pressure regulator’s fuel return
port and install a 3/4"-16 thread plug and o-ring in the fuel
pump’s fuel return port. You can find a 3/4"-16 thread plug
at most hardware stores. Do not try to adjust the bypass
adjustment - pump damage may result.

Be sure to install a suitable fuel filter (maximum 100 micron)
between the fuel tank and the fuel pump. Mallory COMP
FILTER

®

Series Part Nos. 3140 or 3500 are recommended.
This prevents debris from becoming wedged in the fuel
pump’s Gerotor and locking it. An additional filter(s)
(maximum 40 micron) should be installed just before
the carb(s).

PARTS INCLUDED IN THIS KIT:

1 COMP PUMP®Series 250 Electric Fuel Pump
3 Fittings, 3/4" - 16 x #8 AN Flare
3 O-rings, Nitrile 0.644ID x 0.087 thickness

NOTE: DO NOT OPERATE THIS PUMP
WITHOUT FUEL EXCEPT FOR BRIEF
PERIODS WHILE PRIMING

SPECIFICATIONS

Maximum recommended operating pressure: 20 PSI

(factory set at approximately 15 PSI)

Maximum dry suction lift: 3 feet. This is maximum distance
above the fuel level in the fuel tank that the fuel pump will
prime itself.

Oil pressure switch rating: 15 AMP

Fuel pump over current protection: 15 AMP fuse

Fuel application: Part No. 5250, Gasoline; Part No. 5250A,

Alcohol / Methanol

2 www.mrgasket.com MALLORY IGNITION

CARB

FUEL

FILTER

REGULATOR

FUEL

PUMP

FUEL RETURN

FUEL RETURN

PORT

FUEL
FILTER

FUEL
TANK

FIGURE 1

FIGURE 2

FIGURE 3

MOUNTING PROCEDURE

Step 1

Mount the pump as close as possible to the fuel tank in a
well ventilated area with minimal exposure to road debris.
Avoid exposing the pump and fuel lines to moving parts
and hot surfaces, such as the exhaust system.

The pump should be mounted at tank level or below.

NOTE: Increasing distance between pump and tank will
decrease pump efficiency.

Step 2

Using the pump mounting bracket as a template, locate
mounting holes on a solid member, such as the vehicle
chassis. Drill clearance holes for 5/16" bolts. NOTE: To

ensure against a potential fire hazard from pump
flooding, mount the pump in a vertical position with
the motor on top.

See Figure 1.

Step 3

To prolong pump life and efficiency, a high volume fuel filter
such as the Mallory COMP FILTER

®

Series 500 Fuel Filter
(Part No. 3500) must be installed between the pump and
fuel tank. Connect #8 AN fuel lines as shown in Figure 2 for
Standard Regulator or #10 AN lines as shown in Figure 3
for Return (Bypass) Style Regulator.

Step 4

Be sure to install one of the Mallory High Volume Fuel
Pressure Regulators between the pump and carburetor.
For maximum efficiency, mount the pressure regulator
as close as possible to the carburetor. See instructions
packaged with the pressure regulator. Make sure all
fittings are tight so that air cannot enter the system.

(WITH STANDARD FUEL PRESSURE REGULATOR)

(WITH REGULAR STYLE FUEL PRESSURE REGULATOR)

FUEL OUTLET

3/4" - 16 (#8AN)

FUEL INLET

3/4" - 16 (#8AN)

FUEL RETURN 3/4" - 16
(MUST BE PLUGGED
WHEN USING A RETURN
[BYPASS] STYLE
REGULATOR

NITRILE O-RING

NITRILE O-RING

BYPASS ADJUSTMENT

NOTE: Bypass pressure above
20 psi will make the pump draw
more current and significantly
reduce pump life.

RED (+)

BLACK (–)