Idle Feed and Accelerator Pump Restrictor Removal, Installation and Troubleshooting Instructions SUM-M08040 M2008 Squirter Restriction Kit SUM-M08041 M2008 Idle Feed Restriction Kit

WARNING! These instructions must be read and fully understood before beginning installation. Failure to follow these instructions may result in poor performance, vehicle damage, personal injury, or death. If these instructions are not fully understood, installation should not be attempted.

TROUBLESHOOTING

Accelerator Pump Discharge Restrictions At times, it may be necessary to change the accelerator pump discharge nozzle restrictions in the carburetor to improve low end performance. In this kit, there are various sizes to allow for proper tuning of most applications. The number stamped on the top surface of the restriction, correlates to the size of the restriction in thousands of an inch. It is recommended to change one size up or down at a time. In most cases, it’s only necessary to change the size of the primary restrictions. If you have purchased a mechanical secondary carburetor it may be necessary to change the secondary accelerator pump discharge nozzle restrictions. The following are a few examples to use as a guide when changing these restrictions;

1. Vehicle hesitates immediately off idle. This usually indicates a lean condition or not enough accelerator pump discharge fuel. To correct this, increase the accelerator pump discharge nozzle restrictions one size.

2. Vehicle accelerates then lies down or falls over with a puff of black smoke from the tail pipe. This usually indicates

accelerator pump discharge restrictions that are to large. Decrease the size.

3. The carburetor is equipped with a green accelerator pump cam, which is designed to give a very fast delivery of accelerator pump fuel and empties the pump cavity quickly. If a longer duration of accelerator pump shot is needed, switch to a pump cam that has a more gently sloped ramp to it such as a pink cam.

4. If you have poor low end drivability, please refer to the section on changing Idle Feed Restrictions before changing

accelerator pump discharge restrictions. This may correct you problem.

5. If the hesitation occurs when the secondaries open on a mechanical secondary carburetor, but does not hesitate when the primaries only open, then change only the secondary accelerator pump discharge nozzle restrictions.

6. If a mechanical secondary carburetor hesitates when accelerated to wide open, increase the primary side accelerator pump

discharge nozzle restriction one size, then the secondary accelerator pump discharge nozzle restrictions one size at a time until the hesitation is eliminated.

Idle Feed Restrictions At times, it may be necessary to change the idle feed restrictions in the carburetor to improve low end performance. In this kit, there are various sizes to allow for proper tuning of most applications. The number stamped on the top surface of the restriction correlates to the size of the restriction in thousands of an inch. If you need to “richen” up the low end you will need to increase the size of the restrictions. Conversely, if you want to lean out the low end you will decrease the size of the restrictions. Do not increase or decrease the restrictor size more than one size at a time. In most cases, it’s only necessary to change the size of the primary restrictions. It should not be necessary, in most cases’ to change the secondary idle feed restrictions. Remember, after each idle feed restriction change, you must re-adjust the idle mixture screws. The following are a few examples to use as a guide for when to change these restrictions;

1. If the low end drivability seems sluggish, spark plugs show black or dark, or the tail pipe shows black, it may signal that you need to reduce the size of the idle feed restrictions. First check to make sure the idle mixture screws are adjusted properly. Mixtures screws set too rich can cause the same condition. If this is not the case, reduce the size of the idle feed restrictions. Also, if the vehicle mileage is poor and you do an extensive amount of city driving, it may be beneficial to reduce the size of the idle feed restrictions.

2. If the vehicle surges at low speed it is signaling that the idle feed restrictions may be to lean. First, check to make sure

the idle mixture screws are adjusted properly. Mixtures screws set to lean can cause the same condition. If this is not the case, increase the size of the idle feed restrictions.

3. Hesitations that are not easily cured with changing of the accelerator pump discharge restrictions or the accelerator

pump cams usually signal that the idle feed restrictions are too small creating a lean condition. Increase the size of the idle feed restrictions.

2

REMOVAL AND INSTALLATION OF BOOSTER CLUSTER Removal

1. Loosen the (3) three screws holding the choke housing to the carburetor and remove the clip which secures the choke

rod to the choke housing. Remove the air cleaner stud and the (8) eight screws securing the airhorn (Fig. 1). Remove the airhorn carefully to prevent damage to the floats.

2. Remove the screw holding the booster cluster to the main body (Fig. 1), then remove the booster cluster. CAUTION: The pump check weight and check ball are underneath the nozzle screw. Do not lose these items. If weight and check ball are removed, the check ball should be replaced first followed by the weight. Remove the booster cluster screw gasket and the booster cluster gasket and discard.

Figure 1

Installation

1. Install the booster cluster with the new gasket provided. Install the booster cluster screw. The hollow pump check weight will rest inside the hollow booster cluster screw when properly installed. Tighten the Booster cluster retaining screw to 15 in/lb.

2. Reinstall the airhorn being careful not to damage the floats. Use a new airhorn gasket if necessary Summit Part# SUM-

M08001. Secure with the (8) eight airhorn screws, torque to 20 in/lb. Reinstall the air cleaner stud and torque to 20 in/lb.

3. Install choke rod through the hole on the choke housing lever. Ensure the choke rod end is underneath the fast idle

cam extension. Install retaining clip. Install the (3) three choke housing retaining screws. Summit Racing Equipment 1200 Southeast Ave Tallmadge, OH 44278

Technical Service: 1-330-630-3030

Fax: 1-330-630-5333

For online help, charts, guides, and tech tips, log on to: www.summitracing.com Printed in U.S.A. Copyright © 2008 Date: 11-10-2008 199R-10497