The CVP Hi-Flow Fuel Inlet Elbow for Harley CV
and Keihin butterfly carburetors
The stock Harley fuel elbow found on CV carburetors has long been known
to be the achilles heel of this carb. The inlet is not only restrictive
but made of plastic which breaks easily.
The plastic fuel inlet can
crack and leak when removing the original crimp clamp or if over
tightened. Also the manner in which the plastic elbow is formed onto a
brass insert restricts flow.
If you have ever wanted to replace
the fuel inlet and increase flow to your CV carburetor read on.
order to remove the original fuel inlet you must first break off the
plastic molded elbow. Don't be shy, get out your favorite hammer or pliers
and simply snap the plastic portion off of the carb. It is important to
note the angle/position of the original elbow so the fuel line is routed
Once the plastic is removed only the brass inner
portion of the elbow will remain. Some have had luck pulling this piece
out with vise grips and brute stength, but more often than not this only
results in the brass piece spining endlessly. Below is listed the tools
and technique for pulling the fuel elbow insert with ease.
1. Wrench or pliers
2. 1/4"-20 thread
3. 1/4" x 3" long machine screw
4. 1/4"-20 nut
1-1/4" fender washer (min 1/4" hole)
6. 3/8" x 2" pipe nipple or
7. Replacement inlet
CAUTION: Never Heat a
Carburetor to Remove or Loosen Parts!
Fuel elbow removal tools
||Using a 1/4"-20 tap and T-handle, begin twisting the tap
clockwise into the brass stub tapping threads approximately 1/4" in.
Tapping threads all the way through is not necessary as you only
need enough for the screw to grab while pulling the old piece out.
To prevent excess brass particles from falling back into the
carburetor it is advised to hold the carb with the inlet piece
facing down so that particles fall away rather than being pushed
into the float bowl while tapping. Remove all brass
filings/particles before continuing.
Tapping the brass stub
||Assemble the puller. Place the pipe nipple (or deep socket) over
the brass stub. Thread the nut onto the 3" screw up to the screw
head, then pass the screw through the fender washer. Insert the
screw/nut/washer assembly through the pipe nipple or deep socket and
thread the screw end a few turns into the tapped brass piece. You
only need to thread in enough to grab.
With a wrench begin
to turn the nut down (clockwise) forcing the screw to lift the brass
piece out. It may be easier to hold the screw at the same time with
a srewdriver. Once the piece begins to move it will pull out like
Pull the old fuel inlet
||Remove the pipe nipple, it may be wedged onto the
carburetor. Thoroughly clean the fuel insert passage to make sure it
is free of any brass filings. Soapy water will wash away any fine
particles and not harm the internal parts. Be sure the carburetor is
clean and dry.
Installing the new fuel elbow will vary
depending upon brand or type. Harley dealers sell both an OEM
and brass inlets that can be pressed in. Some catalogs carry an
OEM replacement inlet but it has the same plastic elbow (not
recommended), while others sell a brass inlet made from a 2-piece
design (also not recommended). CV Performance recommends the CVP
Fuel Max Inlet made from a single solid piece of brass
which is both leak-proof and can improve flow by more than
40% over some other models.
Installing the new inlet elbow
installing a solid brass or CVP inlet and a press is not available
simply tap the inlet into the carburetor with a small mallet. You
may also place a piece of wood over the elbow and tap in with a
regular hammer. The smooth end presses into the carb and the barbed
end is meant to grip the fuel hose.
The brass inlet will
self-seal when it is pressed in as long as the carburetor inlet
passage is free of debris and not damaged or cracked. A thin layer
of blue locktite around the fitting to help seal but care should be
taken not to allow any to drip back into the fuel passage as it will
damage the rubber tip on the float needle (plunger).
Note that while working on the carburetor or any fuel system,
care should be taken to keep away from any open flame or heat
source. NEVER try to loosen carburetor parts using
Replacing the Harley fuel elbow can help guarantee a
leak free carburetor, and if installing a hi-flow CVP
Fuel Max Inlet also provide increased flow.
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