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    Setting and Leakdown Procedure for Enderle Barrel Valve **NEW** Major Changes Added

    Since the idle mixture is controlled by the metering valve, the purpose of adjusting is to achieve a richer or leaner idle condition. The linkage between the valve and the throttle shaft consists of a threaded turnbuckle, one end has a right-handed thread and the other has a left-handed thread. Loosen both locknuts and turn the turnbuckle. To richen the idle, adjust the turnbuckle so that the arm on the metering valve moves in the open throttle direction. To lean the idle, reverse the procedure. One half to one turn should be ample. Retighten the locknuts. Always set butterflies BEFORE you perform your leak down test. If you don’t have a leakdown tester, we sell a nice one with -6AN and -8AN fittings listed under Tools and tuning aids ………….You will need one eventually,,,,might as well quit fiddling around.   link to tester

    Caution :  If attempting to use an automotive cylinder leakdown tool- it may read Backwards and ruin your engine

    ENDERLE: Black Square, K Valves, and Older  Red Barrel Valves :

    For Enderle barrel valves for unblown engines, Bug, Bird, BAU,  the correct spool is a #32 or #33 – use 25-30% leakage for Alcohol .   18%-22%  for E-85 12%-18% for Gas –  The Smaller the engine the less leakage %

    For 8 Stack Engines – Butterflies to .002”  to .003”  for Alcohol and .004”  for Gas-E-85   before Doing Leakdown-  Butterflies are VERY Important  on  8 stacks to make them idle properly.

    Blown Alcohol– With a #17 spool in the SQUARE BARREL VALVE  for blown alcohol use 60%-75 % leakage. The larger the engine, and with more boost, you increase it to more leakage-  Never go past 85% – Crack the butterflies to .010″ for small engine  .012” for  engines over  550 cu in
    E-90 and E-98 Should be treated like Blown alcohol  and requires a 17 Spool
    Nitro with a  Square Valve-    up to 50%  use 85% leakage and  .015” for Butterflies  with a 5 lb checkvalve  – the 17 Spool will not be good for over 50% – Order a #15 Spool from our site.

    * Always set butterflies with a feeler gauge Before preforming the leakdown test
    Blown Gas or E-85  – With a #12 Spool for use 25% to 33%  and crack the butterflies open to about .012″-.013″-    E-90 and E-98 Should be treated like Blown alcohol  and requires a 17 Spool

    On K Valves and older Enderle Barrel valves there is no number stamped on the spool- You will need to send us a picture of your Spool for identification.

    There are 4 Spools Available for the K style Valve –   Unblown- Blown Gas-E-85  –  Blown Alcohol-    Blown Nitro ( over 50% )

    Leakdowns are the same as above for the Square valve.

    On Unblown and Blown Gas and E-85 Setups –  The Pill MUST be relocated  to External by pass instead of being screwed into the Black Square Barrel Valve-   This can be done several ways  , typically be using a 7001 , 7002, 7002A,  fitting and a 7003  pill holder-  When you re locate it – you must install a  Blank Pill inside the screw in hole where the pill was located when  it was Blown Alcohol setup – You can also use a Remote pill holder like a Hilborn, Kinsler, or other down near the pump if you desire.

    Unblown engines use a 2 #  Checkvalve    6001-2    at the pill-  Blown Alcohol  engines use a 6001-5    Blown Nitro and some high boost Big Blown alcohol engines use a 6001-7  lb valve

    In every case, you must cap the secondary valve and idle check valve or you will get a phony reading.   ALL Brass Check valves get capped during leakdown procedure.

    A barrel valve without sufficient “leakage” will not allow the engine to start- with too much leakage it will idle down too slow and be obviously rich.  If it starts and quits, keep richening the barrel valve until it continues to run.


    Call Mike Chilando @ 615-457-3192  or e mail him at  for more detailed info, and he will help you.

    Thank You,