2. Throttle Leakage

Table 5-1-8: Calibration Recheck Specifications

Throttle leakage is set with the throttle lever held firmly closed.

The pump is operated at rated speed and the fuel delivery is

measured for one minute.

Recheck from one test stand to another or from tested engine

Governor Cut-Off

-O to +10 RPM

Rated speed to

to test stand can vary +15 cc from published value (I.e.; 35 cc

RPM

from published

50 RPM above

throttle leakage can be 20 to 50 cc at reflow), If leakage is 100

values

rated speed

cc/min, or less. When leakage is 100 cc/min. or over, It can

vary +15 cc to - 35 cc/min. (I.e., 150 cc/min. leakage can be

Manifold pressure

+10%or+ 1 PSI+ 30% from

115 cc to 165 cc/min. at reflow).

at idle speed

which ever is

published value

larger

3. Idle Speed Manifold Pressure

Manifold pressure

+- 2 PSI from

Same variance as

a. Recheck from one test stand to another, manifold

at rated speed

published value

on engine mani-

pressure can vary _ 10% from specifications or + 1 PSI

fold pressure

whichever is larger, (i.e.; 20 PSI @ 500 RPM can be 18-22 PSI

tolerance plus

at recheck or 3 PSI @ 500 RPM can be 2-4 PSI at recheck).

an additional

+2 PSI

b. Recheck after engine adjustment, manifold pressure

Throttle Leakage

+ 15cc If 100 cc/min

or less

can vary + 30%/0 from specifications, (i.e., 20 PSI @ 500 RPM

+ 15cc to -35cc/min

if over 100 cc/

can be 14-26 PSI at recheck).

min.

Idle Setting

-2 to + 4 PSI

4. Manifold Pressure at Rated Speed

First manifold

+- 1 PSI from published values Rated

pressure check

speed manifold pressure must first be

a. Recheck from one test stand to another, manifold

point

to spec. by adjusting flow valve.

pressure can vary + 2 PSI from published specifications, (i.e.,

126 PSI manifold pressure can be 124-128 PSI at reflow).

Second manifold

A

If first check point is +1 PSI, sec-

pressure check

ond check point to be from pub-

Suction vacuum must be set at 5 inch Hg.

point

lished min. spec to +1 PSI

above published max.

b. Recheck after engine adjustment; manifold pressure

can vary the same as the on engine fuel pressure tolerance

B

If first check point is -1 PSI, sec-

plus an additional + 2 PSI, (i.e.; if on engine pressure

ond check point to be from pub-

lished max. spec to -1 PSI

specification is 114-126 PSI or 6 PSI the tolerance for the

below published min.

manifold pressure at recheck is (+ 6) + (+ 2) = + 8 PSI. Then

C

If first check point is within pub-

126 PSI manifold pressure can be 118-134 PSI at reflow).

lished spec. second check po int

must be within published spec.

Suction restriction must be set at 5 inch Hg.

Manifold pressure

-+ 1 PSI from published value.

5. Manifold Pressure Check Point

at Wt. Assist

check point

Recheck pump at rated speed and obtain exact manifold

pressure per calibration specification by adjusting the flow

control valve.

1. Governor Cutoff R.P.M.

Suction restriction must be set at 5 inch Hg.

The governor cutoff R.P.M. is defined as the RPM where the

l. First check point can vary ± 1 PSI from the published

manifold pressure starts to decrease from the maximum

specifications, (i.e.; 100-106 PSI @ 2000 RPM can be 99-107

observed pressure as the speed is increased.

PSI at reflow).

a. When checking from one test stand to another, cutoff

II. Second check to be as follows:

speed can vary _ 10 RPM from the published cutoff RPM

(i. .; 2520-2540 RPM cutoff speed, reflow can be 2510-

a. If pump checks + 1 PSI at first check point, it must be

2550 RPM).

at published minimum specifications to + 1 PSI above

Suction vacuum must be set at 5 inch Hg.

published maximum specifications at second check point, (i.e.;

75-81 PSI @ 1500 RPM can be 75-82 at recheck).

b. Recheck from engine test to test stand, cutoff speed

b. If pump checks - 1 PSI at first check point, it must be

can be from rated speed to 50 RPM above rated speed (i.e.;

published maximum to - 1 PSI below published minimum

rated speed 2500 RPM, cutoff speed at reflow can be 2500-

2550 RPM).

Suction vacuum must be set at 5 inch Hg.

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