FORM 1548 (REV. A) 05/02
INSTALLATION INSTRUCTIONS
®
INLINE RETURN REGULATOR
PART NO. 4316
1. Mallorys Inline Return Regulator is an adjustable
bypass style fuel pressure regulator designed to
regulate pressure in a carbureted fuel system.
2. The regulator must be mounted in the return line.
For best results, the regulator should be mounted
within 3 feet of the carburetor(s). See Figure 3 for
typical installations.
3. Fuel pressure is adjusted by loosening the jam nut
and turning the adjustment screw. The adjustment
range is approximately 3-12 PSI. Exact range depends on
the size of the fuel pump and return line (see Figure 1).
4. This regular is designed to work with pumps up to 300 GPH.
5. Fittings are included to connect the regulator to 8AN fuel
lines. Alternate fittings may be used to connect the regulator to other sizes/types of fuel lines.
6. Repair kits are available and include all necessary o-rings.
These kits can be used for repair, or to convert from gasoline to alcohol.
Use Kit #3173 for gasoline applications
Use Kit #3174 for alcohol applications.
FIGURE 1
FEED LINE SIZE
Up to 500 HP: 6AN or 3/8" Hardline
Up to 750 HP: 8AN or 1/2" Hardline
Up to 1250 HP: 10AN or 5/8" Hardline
RETURN LINE SIZE
Up to 90 GPH: 6AN or 3/8" Hardline
Up to 200 GPH: 8AN or 1/2" Hardline
Up to 300 GPH: 10AN or 5/8" Hardline
Lubricate o-rings prior to assembly.
7. This regulator is assembled with o-rings for use with gasoline. O-rings are included for use with alcohol. If alcohol fuel
is used, disassemble the regulator and replace the o-rings
with those supplied.
8. Because this is a return style regulator, the bypass at the
pump must be disabled. If you are using a pump with an
external bypass (such as Mallory 250), place a plug in the
bypass outlet.
If you are using a Mallory 70, 110, or 140 pump, the bypass
spring must be replaced with the bypass spacer included
with this regulator (see Figure 2). Replace the spring with
the spacer. Apply thread sealant to the bypass plug and
tighten the plug until snug. Do not overtighten. Replace and
tighten the jam nut (see Figure 2).
If you are using a non-Mallory pump, contact the manufacturer for information on how to disable the bypass.
70, 110, OR
140 PUMP
®
FIGURE 2
--OVER--
FIGURE 2
TYPICAL INSTALLATIONS
MALLORY IS A DIVISION OF THE MR. GASKET PERFORMANCE GROUP
550 MALLORY WAY, CARSON CITY, NEVADA 89701
(775) 882-6600 FAX (775) 887-4326
www.mrgasket.com
FORM 1548
(REV. A) 05/02
Made in U.S.A.
Printed in U.S.A.