McCulloch MT3075 - TROUBLESHOOTING THE ENGINE

CORRECTIVE ACTION
Follow instructions in the User Manual.
Have carburetor adjusted by an
Authorized Service Center.
Clean / gap or replace plug.
Replace fuel filter.
Move to RUN position.
Replace spark arrester screen.
Remove, clean and reinstall filter.
Have carburetor adjusted by an
Authorized Service Center.
Have carburetor adjusted by an
Authorized Service Center.
Clean / gap or replace plug.
Have carburetor adjusted by an
Authorized Service Center.
Use properly mixed fuel (40:1 mixture).
PROBLEM
Unit won’t start or starts but will not
run.
Unit starts, but engine has low
power.
Engine hesitates.
No power under load.
Runs erratically.
Smokes excessively.
PROBABLE CAUSE
Incorrect starting procedures.
Incorrect carburetor mixture adjustment
setting.
Fouled spark plug
Fuel filter plugged.
Incorrect lever position on choke.
Dirty spark arrester screen.
Dirty air filter.
Incorrect carburetor mixture adjustment
setting.
Incorrect carburetor mixture adjustment
setting.
Incorrectly gapped spark plug.
Incorrect carburetor mixture adjustment
setting.
Incorrect fuel mixture.
9 - TROUBLESHOOTING THE ENGINE
19
10 - PRIST LIST
No. Parts No. Description No. Parts No. Description No. Parts No. Description
1 9295-310501 SPARK PLUG
9228-334507 FILTER ASS'Y 9068-330306 HOUSING, HANDLE-UPPER
2 9SGEB-05-10 SCREW
9287-334501 CARBURETOR 9SKKBY10/24-1 SCREW
3 9211-334502 PLATE (SPARK SIDE)
9014-334505 CARBURETOR GASKET 9068-330305 HOUSING, HANDLE-UNDER
4 9012-330301 GROMMET
36 9SKKB-05-19 SCREW 9NAC-10/24 NUT
5 9SRCB-05-22 SCREW
9211-334503 PLATE 9027-332101 REDUTION
6 9SXMBJ05-50 SCREW
9012-334501 GROMMET 9228-332627 HOUSING ASS'Y
7 9228-334503 MUFFLE ASS'Y
9072-334501 INSULATOR 9228-330319 STRINGHEAD ASS'Y
8 9014-GP0102 MUFFLE GASKET
9014-334506 INSULATOR GASKET 9110-330301 GEAR HOUSING ASS'Y
9 9211-334501 MUFFLE PLATE
9157-332101 SEAL 9125-332601 ACCESSORIES
10 9017-334501 COVER (FLYWHEEL SIDE)
9228-334501 CRANKCASE ASS'Y 9131-330304 COLLAR
11 9SGEB-04-10 SCREW
42-1 9151-334502F CRANKCASE (STARTER SIDE) 9124-330309 SPLINE SLEEVE
12 9017-334502 GASKET
42-2 9PA-03-08S PIN 9111-330301 NUT
13 9014-334507 GASKET
42-3 9151-334501F CRANKCASE (FLYWHEEL SIDE) 9228-330324 COVER ASS'Y
14 9292-334501F CYLINDER
42-4 9SGEB-05-20 SCREW 9017-330315 COVER
15 9014-334501 GASKET
9DB-620101 BEARING 9SKKBY10/24-0.5 SCREW
16 9189-334501 PISTON RING
9014-334502 GASKET 9250-330301 KIT, KNIFE
17 9131-334501 CIRCLLP
9157-334501 SEAL 6NGB-10/24 NUT
18 9115-334501 PISTON PIN
9CB-32 C RING 9228-334510 HANDLE ASS'Y
19 9290-334501 PISTON
9169-334501 FLYWHEEL 6SDABB04-12 SCREW
20 9067-334501 AXLS COVER
9228-334506 FUEL TANK ASS'Y 9068-332103 HOUSING, HANDLE
21 9NR-KV9129.8 NEEDLE BEARING
9SKKBY05-18 SCREW 9010-332103 WIRE ASS'Y, SWITCH
22 6221-830301 KEY
9NHC-08 NUT 9010-334501 THROTTLE CABLE
23 9228-334502 CRANK/ROD ASS'Y
9WFB-06-15 WASHER 9059-332101 HOSE
24 9288-334501-CH IGNITION COIL
9176-GP0101 CLUTCH (WITH SPRING) 9028-332101 TRIGGER
25 9SGEB-05-20 SCREW
9WWB-08 WAVE PLATE 9024-332102 SPRING
26 9010-332102 COIL WIRE
9214-GP0101 SCREW 9176-332101 LIBERATE SHAFT
27 9SGKB-05-12.5 SCREW
9228-334508 TRANSMISSION SUPPORT ASS'Y 9024-332103 SPRING
28 9228-334504 STARTER HOUSING ASS'Y
9NDB-05 NUT 9176-332102 LIBERATE CHUNK
29 9228-MD0107 PAWLS ASS'Y
9SDABM05-25 SCREW 6SLABB3.5-10 SCREW
30 9228-334512 FILTER COVER ASS'Y
9SKKB-05-16 SCREW 9022-330502 SWITCH
30-1 9134-334501 KNOB
6SDAB-05-08 SCREW 9068-332104 HOUSING, HANDLE
30-2 9017-334505 FILTER COVER
9WFB-5.64-12 WASHER 9076-GP0101 SEAL
31 9183-334501 FILTER
9SGKBY10/24-0.625 SCREW
32 9SGEB-05-52 SCREW
9228-330336 HANDLE ASS'Y
35
34
33
40
39
42
41
38
37
46
45
44
43
50
49
52
51
48
47
56
55
54
53
60
59
62
61
58
57
62-4
67-2
67-3
68
68-1
62-3
62-2
62-1
66
65
67-1
67
64
63
69
68-4
68-3
68-2
69-4
69-3
69-6
69-5
69-2
69-1
69-10
69-9
69-8
69-7
70
69-13
69-12
69-11
MODEL : MT3075
20