Features / Model & 1st year built

MC10 MC20 MC30 MC40 MC-45 MC70 MC75 MC100 1966 MC101 1967 MC101A 1969 MC101AA 1972 MC101B 1974 MC101C 1969 MC101D 1971 MC101M/C 1973

Bore 
2.125  2.125  2.165  2.165  2.165  2.217  2.250  2.250          2.280            2.280               2.280               2.280             2.280              2.280             2.280 
Stroke
1.500  1.635  1.635  1.635  1.635  1.835  1.835  1.835          1.835           1.835               1.835               1.835             1.835              1.835             1.835 
Displacement
5.3?     5.8      6.05   6.05    6.05   7.08     7.29   7.29            7.5                7.5                   7.5                   7.5                7.5                  7.5                 7.5

 
McCulloch Super / 101 Series Identification Chart 

For Reference only   Updated: 14th March 2008
Primary Areas for Positive Block Idendification 
MC10    MC20    MC30    MC40     MC-45    MC70    MC75    MC100 1966    MC101 1967    MC101A 1969     MC101AA 1972    MC101B 1974    MC101C 1969   MC101D 1971   MC101MC 1973                       
Block part number see at bottom of page
Intake Open Below Cylinder wall - large or small
   N       N         N        Y        Y         Y         Y           Y                 Y                   Y                     Y                    Y                   Y               Y                     Y
Fixed head
   N       N         N        N        N         Y         N           N                 N                   N                     N                    N                   N               N                     N 
Copper o-ring head gasket
 
  N       N         N        N        N         N         N           N                 N                   Y                     Y                    Y                   Y                Y                    Y
Flat alloy head gasket
   Y       Y         Y        Y        Y         N         Y           Y                 Y                   N                     N                    N                   N                N                    N
Large PTO bearing (pn 6204)
 
   ?       ?          ?        ?        Y          ?         Y           Y                 N                   N                     N                    N                   N                N                    N
Oiler mount nub
   Y       Y          Y       Y        Y          Y         Y           Y                Y                    Y                    Y                   Y/N                 Y                 Y                   Y
Bolt-in transfer port cover
 
   N      N          N        N       N          N         N           N                Y                    N                    N                     N                   Y                 N                  N 
3rd port intake
    Y      Y          N        N       N          Y         N           N                N                    N                    N                     N                   N                 N                  N
2 Finger ports intake port
    N      N          N        N       N          N         N           N                N                    Y                    Y                     Y                   N                 Y                  Y
Factory 9  port  transfer ports
    N      N          ?         Y       ?          N         Y           N                N                    N                    N                     N                   N                 N                  N
Machined recess for rod bolt clearance
    N      N          N         N      N          N         N           N                Y                    Y                    N                     N                   Y                 N                  N
Cast-in recess for rod bolt clearance
    N      N          N         N      N          N         N           N                N                    N                    Y                     Y                   N                 Y                  Y
Ribs in exhaust port
     Y     Y          Y         N      N          N         N           N                Y                    N                    N                     N                   Y                 N                  N
Recess for square exhaust gasket
     N     N         N           N      N         N         N           N                 N                    N                    N 
                   Y                    N                N                  N
MC10    MC20    MC30    MC40     MC-45    MC70    MC75    MC100 1966    MC101 1967    MC101A 1969     MC101AA 1972    MC101B 1974    MC101C 1969   MC101D 1971   MC101MC 1973 

Round Cylinder Head
 
   Y      Y        Y            ?       ?         ?         N           N                 N                    N                     N                   N                   N                 N                  N
RH Thread PTO crankshaft
    Y       Y       Y            Y      Y         Y         Y           N                 Y                    Y                     Y                   N                   N                  N                  N
LH Thread PTO crankshaft
    N       N       N            N      N         N         N            Y                Y                     Y                    Y                   Y                   Y                  Y                  Y
Painted block
    Y       Y       Y            Y      N         N         N            N                N                    N                     N                   N                   N                  N                  N
Yellow fan shroud & head cover
    Y       Y       Y             Y     Y          Y        N            N              
Black fan shroud - Yellow head cover
 
   N       N       N             N     N          N        N             ?               N                     N                    N                    N                  N                   N                  N
Black fan shroud - Chrome head cover
    N       N       N             N     N          N        N            N                N                    N                     N                    N                  N                   Y                  N 
Air horn and wider flywheel cover
    N       N       N             N     N           N       N             N               N                    Y                     Y                   Y                   N                   N                  Y
Chrome shrouds - flywheel & head
    N       N       N             N     N           Y       Y             ?                Y                    Y                     Y                  Y/N                 N                  N  
Blue fan shroud & red head cover
    N        N      N             N     N           N       N             N               N                    N                     N                   Y/N                 N                  N                  N
White fan shroud/red head  cover
 
   N        N      N             N     N           N        N            N               N                    N                     N                     N                  N                  N                  Y
Yellow fan shroud & chrome head cover
     ?         ?      ?             ?      ?           N        N            N               N                    N                    N                     N                   N 
                N        ..         N
Secondary areas which are not a positive ID of a block as parts may have been repainted or installed from other models
Key: Y = Yes   Feature exists          N = No   Feature did not exist


 
Cylinder Part Numbers

Mc 10  Mc 20   Mc 30   Mc 40   Mc 45  Mc 70  Mc 75   Mc 100   Mc 101   Mc 101a   Mc 101aa    Mc 101b    Mc 101c     Mc 101d       Mc 101m/c
48612   48871   48992   47749   47878  47795   47873   47873B   66019      84534                          92909        66019          84534            66019
                                                                                                                                                                                   
89390
 
Carby part no

Mc 10    Mc 20   Mc 30   Mc 40   Mc 45    Mc 70      Mc 75    Mc 100   Mc 101   Mc 101a   Mc 101aa    Mc 101b    Mc 101c     Mc 101d       Mc 101m/c


50070c / 48907 / 48907 /           / 48890b / 48907a / 48907b / 48890b /   68907 /     68886   /                   / 88845 /                      / 84446 /
                                                                                                     /   69812 /                                     / 68886 /       82894      /  84947 /