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Technical Information · issue 56 of 2002

Technical Description; Specifications; Mounting the MultiTools; Air Filter; Special Optional Accessories; Service Note; Summary

IssueTI 56/2002

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TI 56/2002 page 1
Technical Information

                                                                                                56.2002
New STIHL MM 55 MultiEngine – Series 4601
New STIHL BF-MM, BK-MM MultiTools – Series 4601

Contents
1.   Technical Description

2.   Specifications
3.   Mounting the MultiTools
4.   Air Filter
5.   Special Optional Accessories

6.   Service Note
7.   Summary

The new STIHL MM 55 MultiEngine is a universal           The MultiEngine MM 55 with the BF-MM pick tine
unit for a range of different applications.              cultivator is designed for both occasional and
It comes standard with the BF-MM cultivator              municipal users.
MultiTool. Further MultiTools will be available by the
                                                         Typical applications are breaking up and loosening
end of 2003.
                                                         previously cultivated soil, trenching or furrowing and
                                                         working in soil improvers.

TI_56_2002_01_01_01.fm                                                                          english / USA
)m~ge 2                                                                        Technical Information 56.2002

.     Universal unit for wide range of applications,
      different MultiTools can be used.
.     MultiTools are quickly changed and cleaned.
.     Folding handle for simple transportation.
.     Space-saving storage. Folded unit can be hung
      on a wall.
.     Low weight for easy handling; extra weights
      available as special accessory.

                                                                                                             469TI001 KN
.     MM 55 with BF-MM / BK-MM MultiTool
      Working width of 8.9 in (220 mm).

                                                           Left: BF-MM pick tine cultivator
                                                           Right: BK-MM bolo tine cultivator
1.     Technical Description

The worm gear reduces the output shaft speed of
the MM 55 to 190 rpm for tilling soil.
                                                           2.     Specifications

The MultiTools consist of 4 rotor blades with hub
which are mounted on the gearbox output shaft. The         Single cylinder two-stroke engine
MultiTools are held in position by a spring clip and
can be changed quickly and simply.
                                                           Displacement:
                                                           Bore:
                                                                                  1.66 cu.in (27.2 cm3)
                                                                                  1.34 in (34 mm)
1.1    Engine                                              Stroke:                1.18 in (30 mm)
The MM 55 MultiEngine uses the time-proven series          Engine power to
                                                           ISO 8893:              1 bhp (0.75 kW)

4140 engine.
                                                           Idle speed:            2,800 rpm
1.2    Gearbox                                             Max. engine speed:     8,400 rpm
The single-stage worm gear is lubricated for life.         Max. output

The gear ratio is 44:1.                                    shaft speed

                                                           (working tool)         190 rpm
1.3    Approved MultiTools
The following STIHL MultiTools may be mounted to
                                                           Ignition system

the MM 55 MultiEngine:
                                                           Type: Electronic magneto ignition system
MultiTool                       Part No.

                                                           Spark plug (resistor   Bosch WSR 6 F,
BF-MM pick tine cultivator      4601 740 4605
                                                           type):                 NGK BPMR 7 A
BK-MM bolo tine cultivator      4601 740 4606
                                                           Electrode gap:         0.020 in (0.5 mm)

The MM 55 comes standard with the BF-MM                    Spark plug thread:     M 14 x 1.25;
MultiTool (pick tine cultivator) already mounted.                                 0.375 in long
Further MultiTools will be available in the future.                               (9.5 mm)

                                                           Fuel system
                                                           Carburetor: All position diaphragm carburetor with
                                                           integral fuel pump
                                                           Air filter:            Oil-impregnated main
                                                                                  filter, felt prefilter
                                                           Fuel tank capacity:    0.7 US.pt (0.33 l)

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Technical Information 56.2002                                                                                            Page 3

Fuel mixture:              Brand-name grade                            .    Rotate the inner, right-hand blade (2) on the
                           gasoline (pump octane                            shaft until it can be pushed into position – check
                           89) and brand-name two-                          the arrows showing the direction of rotation.
                           stroke air cooled engine                    The hub of the inner blade is larger than that of the
                           oil with the classification                 outer blade.
                           TC
                                                                       .    Rotate outer, right-hand blade (3) on the shaft
Mix ratio:                 50:1 with STIHL 50:1                             until it can be pushed into position – check the
                           engine oil                                       arrows showing the direction of rotation.
                                                                       .    Insert and engage spring clip in the hole at the
Weight
                                                                            end of the shaft – fold the spring clip flat against

MM 55 without              16.3 lbs (7.4 kg)                                the blade.

MultiTool
                                                                       .    Use the same procedure to mount the rotor
MM 55 with                 20.7 lbs (9.4 kg)                                blades on the left-hand side.
MultiTool

BF-MM pick tine            4.4 lbs (2.0 kg)                            4.     Air Filter
cultivator
BK-MM bolo tine            4.4 lbs (2.0 kg)

cultivator

MultiTools
Working width:             8.9 in (220 mm)
Diameter BF-MM             9 in (230 mm)
                                                                                      6
Diameter BK-MM             8.1 in (205 mm)

3.    Mounting the MultiTools                                                                      5



                                                                                                                               469TI003 KN

                                                                       Air filter assembly 4601 007 1007 is used in the
                                                                       MM 55 because of the high level of dust in cultivator
                                                                       operations.
                                                                       An oil-impregnated main filter (5), which retains fine
                                                         469TI002 KN

         3         2                                                   dust, is installed in the filter housing (6) together with
                                                                       the felt prefilter (4).

.    Always wear gloves when working with the                          Always replace the felt prefilter and main filter as an
     MultiTool.                                                        assembly when servicing. Do not clean, dirt can
.    Pull out the spring clip (1) – do not remove the                  remain in filter element even after cleaning and lead
     washer from the shaft.                                            to expensive engine damage.

Arrange the rotor blades in the order they will be
fitted on the shaft, noting the following points:
Left-hand and right-hand rotor blades are different.
The direction of rotation is marked with arrows on
the gearbox and rotor blades, which must match
with each other.

TI_56_2002_01_01_01.fm
)m~ge 4                                                                                 Technical Information 56.2002

5.      Special Optional Accessories                                5.2   Bolo tine cultivator MultiTool
                                                                    The bolo tine cultivator 4601 740 4606 can be used
5.1     Extra weights                                               as an alternative to the pick tine cultivator. It is
The MultiEngine can be retrofitted with the optional                particularly suitable for digging in previously
weights 4601 730 4500 to increase the down                          cultivated, loose soil.
pressure on the MultiTool.

                                                                                                                             469TI006 KN
               1              2
                                                      469TI004 KN

5.1.1 Mounting the extra weights                                    5.3   Spur
Remove the weights from the side without the
square face as follows:
                                                                    Spur 4601 740 4800 is available for convenient
                                                                    control of the power tool with bolo tine cultivator.
.     Take the screw out of the outer weight and                    It slows forward movement and reduces the effort
      remove the weight.                                            required to hold the unit.

.     Unscrew the inner weight and remove it from the               The spur can be adjusted to the required depth.
      bolt.
.     Insert the extra weight with bolt (1) through the

      hole (2) in the flange and rotate it at the same
      time until its square face engages the recess in

      the flange.
.     Screw the weight onto the bolt and tighten it
      down firmly.

.     Tighten down the outer weight with the screw.
                                                                                                                           469TI005 KN

Use the combination wrench to release and tighten
the weights.
One or two 4.4-lb (2kg) weights may be mounted on
                                                                    The spur is mounted to the right-hand side of the

each side to suit requirements.
                                                                    flange with the screw and star knob.
The maximum permissible total extra weight is
8.8 lbs (4 kg). A higher weight may result in damage

to the unit.

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Technical Information 56.2002                                                                Page 5

6.        Service Note
The throttle cable is protected and not kinked in
either the normal operating position or when the
handlebar is folded down.
The throttle cable must be routed as follows to                               4
ensure troublefree operation:
.       through the loop handle (1)
                                                                              3
.       through the throttle cable retainer (2) on the
        frame

.       under the crossmember (3)

.       through the throttle cable retainer (4) on the                   1               2
        outside of the handlebar.

                                                                                                 469TI007 KN
7.        Summary
Item         Part Name                                   Part No.
    1        BF-MM pick tine cultivator                  4601 740 4605

    2        BK-MM bolo tine cultivator                  4601 740 4606
    3        Extra weight                                4601 730 4500
    4        Spur                                        4601 740 4800

    5        Air filter assembly                         4601 007 1007

© 2002 Andreas Stihl AG & Co.                                  Technical Documentation
  Waiblingen                                                   D1/MTK-ja                      7711

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