Bronco Full Size L6-300 4.9L (1987)
4.
If there is no rpm rise and the minimum speed gain specification is "0" rpm, perform the following speed drop test:
NOTE:
Speed drop test information is specified with the artificial enrichment requirements whenever the minimum speed gain specification
is "0" rpm.*
a.
While watching the tachometer, adjust the mixture screw 1/4 turn clockwise (lean). Note the drop in engine speed.
b.
If the measured speed drop is greater than "0" and less than or equal to 40 rpm, proceed to Step G.
c.
If the measured speed drop is more than 40 rpm, return the mixture screw to the position before adjustment. Proceed to Step G.
d.
If the measured speed drop is still "0" rpm repeat steps a, b, and c.
G.
The carburetor fuel air adjustment must have the tamper-resistant feature reinstalled, see Section III.
*Refer to the Special Specifications Issue TSB Publications.