Quick Fuel Technology 4500 User Manual

Installation Instructions Model 4500 Alcohol Conversion Kit

Remove booster pin with dent puller
(sheet metal screw)

Align brass pin with hole in booster, coat
with Loctite®, tap lightly, check alignment
drive until flush with casting recess.

Check alignment before
installing brass pin

Thank you for purchasing QFT’s alcohol conversion kit. This conversion is not particularly difficult

however. there are a few precautions and special instructions you should follow to be certain the conversion
goes smoothly.

1. Completely disassemble the major components; i.e. fuel bowls and metering blocks.

2. With the bowls and blocks removed, remove the locator pins that hold in the booster venturi. The

easiest way to accomplish this is to use a sheet metal screw and a dent remover as shown here.

3. With the booster venturi removed you can now install the new booster assemblies. This is a critical

step and essential that the fit and location of the booster venturi is correct. The casting that holds the
annular insert has a raised line on each side of the locator tab. This is to ensure a tight fit in the main
body casting.

4. Trial fit the booster in the main body to ensure it can be placed deep enough to align with the booster

pin hole in the main body. Look through the booster pin hole on the metering block surface of the
main body, trial fit each booster assembly to check alignment of the booster pin holes. If the holes do
not align it will be necessary to remove material from the raised casting line to achieve a tight fit,
however to enable proper alignment. Material can be removed using a hand file.

5. Once boosters are properly aligned, place a drop of two of Red Loctite® on the booster pin provided.

Insert the booster pin through the main body and into the booster. Lightly tap initially in place with a
small hammer, using a punch with the same OD as the booster pin. Check your progress frequently to
be certain the alignment is maintained. NOTE: When the last step of the booster pin enters the main
body boss the resistance to drive in the pin will become greater. Check the alignment one additional
time then finish driving the booster pin until the pin is flush with the relief cut in the main body.

6. Remove all of the air bleeds from the top section of the main body. Each throttle bore has three

threaded bleed bosses. Working from the outside, in the boss furthest away from the center of the

carburetor install the BLANK bleed. In the boss right next to it, moving toward the center, install the

Install blank air bleed here

Install #40 here
this is the idle
air bleed.

Insert #25 bleed here, this is
the high speed bleed.

Remove roll pin with small punch

Reinstall roll pin with new pump arm as shown.

air bleed marked with the number 40. In the boss next to the accelerator pump discharge nozzle insert
the air bleed marked with the number 25. Repeat this same sequence in the remaining throttle bores.

7. Remove the two pump discharge nozzles (squirters) and stainless screws. In the small parts bag find

the two thick composite gaskets, two thin paper gaskets. Place the composite gasket on the accelerator
pump nozzle hole in the main body, slip the paper gasket over the nozzle screw, then the nozzle
(squirter) and install as a unit on top of the composite gasket, center on the locator tab and tighten with
an 5/32” Allen wrench. The main body portion is now complete

8. Place the fuel bowl so the opening is facing down on your workbench. With a small punch drive the

roll pin that retains the operating arm out of the accelerator pump housing. Install the bent pump arm
supplied with the angled section facing away or pointing down. Tap in the original roll pin with a
small punch until the roll pin is just about flush with the housing. Repeat the process on the second
bowl.

9. While the fuel bowl is still facing down on the workbench remove the old needle and seat assembly.

Hold the adjustment nut with a 5/8” wrench, with a large blade screwdriver loosen the lock screw
while holding the nut. Remove the needle and seat assembly. Set this assembly aside temporarily.

10. Turn the fuel bowl over. With a medium common tip screwdriver, remove the two screws holding in

the float assembly. Remove the entire assembly. Do both fuel bowls at the same time.

11. Lay both floats down on the workbench the same way it came out of the float bowl, with the hinge on

top. Remove the float hinge by pulling it through both the float bracket, float hinge and spring.

12. Reassemble using the new float. Place the float on the workbench in the same orientation as the bowl,

place the hinge on top of the float, and align the holes. Place the small end of the spring in the float
hinge locator hole. Slide the float hinge through the bracket and hinge holes as well as the float spring.
Once all the way through the assembly take the long end of the spring and position it in the cutout in
the float hinge. Use the other float assembly as a guide if needed. Repeat, using the first assembly as a
reference if needed.

13. Install the float assembly into each bowl. Insert the original screws and tighten. Note; these are self-

tapping screws so do not over-tighten.

14. Remove the adjusting nut and lock screw from the needle and seat assemblies. Locate the appropriate

gaskets in the small parts bag. Thread in the new needle and seat assembly into the fuel bow. When
the resistance makes it difficult, turn the fuel bowl upside down, place the large gasket on top of the
adjusting nut, slip the gasket and nut over the notch in the needle and seat assembly. Turn the nut
clockwise until the straight edge of the float is even with the center of the float bracket retainer screws.
With the float bowl still inverted, use a 3/8” drill bit, adjust the needle and seat until the drill just fits