adapter booster contains a 2.0-inch diameter tail fuze. The T46 (series) contains a fuze adapter sleeve for use with 1.5-inch diameter fuzes. MECHANICAL NOSE FUZING.—When you use mechanical nose fuzing, an M148 adapter booster is installed as follows: 1. Unpack  the  adapter  booster  and  remove  the closing plug. 2. Inspect   the   adapter   booster   internally   and externally to ensure all parts, including threads, are clean and undamaged. 3. Inspect the bomb nose fuze cavity. 4. Loosen the setscrew in the bomb body. 5. Screw  the  adapter  booster  into  the  bomb,  and tighten  it  with  a  spanner  wrench  until  it  is firmly seated. 6. Tighten the setscrew in the bomb body against the adapter-booster threads. Installation of Electric and Electronic Tail Fuzes The  Mk  376/FMU-139  series  electric  and  elec- tronic  tail  fuzes  are  currently  being  used  in  the  Navy. The   following   are   general   procedures   you   should follow when working with these fuzes. Refer to figure 13-5 for arming wire installation. MK  376  ELECTRIC  TAIL  FUZE.—Prepare, inspect, and install the fuze as follows: 1. Ensure  that  the  safety  pin  is  installed  in  the pop-out pin. 2. Remove shipping cap. 3. Ensure   moisture   or   foreign   material   is   not present  in  the  electrical  connector  at  base  of fuze. 4. With  thumb,  push  in  on  pop-out  pin;  remove safety pin from pop-out pin. 5. Ascertain    if    resistance    from    pop-out    pin against thumb is present. 6. Reinstall safety pin into pop-out pin. 7. Loosely   install   fuze-restraining   clip   on   the flange of the fuze. 8. Install fuze into tail fuze well, and tighten with spanner wrench until flange is seated. 9. Align pop-out vertical with bomb lugs; tighten fuze-restraining clip. FMU-139 ELECTRONIC TAIL FUZE.— Prepare, inspect, and install the fuze as follows: 1. Ensure that gag rod is secured by safety pin. 2. Verify that red and black striping is not visible on gag rod sleeve. 13-5 ARMING WIRE FAHNESTOCK CLIPS SAFETY PIN SAFETY COTTER PIN ELECTRIC FUZE ARMING WIRE POP OUT PIN FUZE RESTRAINING CLIP CLOSURE RING NOTE: FUZE RESTRAINING CLIP MUST BE INSTALLED, BUT MAY NOT BE EXACTLY IN POSITION SHOWN. MK-376 FMU-139A/B AOf1305 Figure 13-5.—Mk 376 and FMU-139 series electric/electronic fuze arming wire installation.