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PLEASE READ THESE INSTRUCTIONS BEFORE INSTALLING YOUR FUEL SYSTEM. If your injector was shipped directly from the factory, it should be set up for your application. A set of bypass jets is furnished which includes a jetting card showing the engine information and settings. The butterflies and metering valve are set before shipment. The metering valve is set using our leak tester. The leak percentage shown is specific to our leak tester only and will probably be different from other types of leak testers.


When installing the injector on the blower tighten the bolts evenly to prevent distortion. A gasket or silicone seal must be used on the bottom of the injector.


This metering system uses two return lines, each with a check valve. The check valve on the bottom of the metering valve is for the idle circuit and is set to open at 15 psi. The check valve in the tee fitting is the main jet return and opens at 1-2 psi. The main bypass jet is installed in the fitting under this check valve. A blank bypass jet is installed under the 9/16 hex plug on the metering valve and should not be removed. Leakdown %  is usually between 30% and 35%   Alkydigger’s leakdown tester is preferred. The Spool should be #12  only NOT  #17 or #32 in a Square Barrel valve. The bypass pill cannot be located inside the barrel valve – it must be external, and you must install a block off pill inside the barrel valve .  


Each fuel injector is furnished with a set of bypass pills. This bypass controls the fuel mixture at full throttle and has very little effect on the idle. Use a smaller bypass to richen the fuel mixture and larger bypass to lean it. When installing the bypass, make sure it is seated at the bottom of the thread. Do not change the bypass jet to cure problems at idle.


The idle mixture is controlled by the turnbuckle on the side of the injector. To richen the idle, rotate the turnbuckle towards the rear of the injector, (shortening the linkage leans the mixture, lengthening richens the mixture). This adjustment is for idle and throttle response only and has no effect on full throttle operation. The idle speed is controlled by the butterfly shaft stops on each end of the butterfly shaft.  


The fuel system should be drained between races. It is important to lubricate the fuel pump with LPS-3, WD-40, light oil or some other type of lubricant. Remove the inlet line from the metering valve and lubricate the metering piston to prevent stickiness and drying out.


A # 12 inlet line should be used with a -1 size fuel pump. 

For best results the fuel pump should not be higher than the fuel level in the tank. Also, do not use a fuel tank mounted in the rear of the vehicle. The fuel tank must be in front of the engine.

Use a # 6  or #8  line from the pump to the metering valve and for the return lines. The return line must never discharge directly towards the tank outlet. The tank should have at least a 3 gallon capacity and should be vented with a 5/16” or larger hole.


Blown gas engines tend to be very sensitive to barrel valve and butterfly adjustments. Adjust the barrel valve only 1 or 2 flats of the hex bar at a time. If the idle is too lean, the throttle response will be hesitant and there may be a backfire through the butterflies. The exhaust may have some smoke at idle when the idle is set for good throttle response.   Butterfly settings approx .010”  to .012”     


You must use a 3-way fuel shutoff with a return line to the fuel tank. A 2-way style shutoff will damage the fuel pump.

For any additional information call 805-526-3838

Setting up Blown Gas and E-85 Systems