old Suffolk punch mower problem

hi, thanks for looking.

trying to service an old suffolk punch lawnmower. the one with the petrol can that hangs on the frame.

the mower starts fine but does not have enough power to move the blades and rollers. any ideas ?

 

Sounds like something has seized. With the motor shut down, how hard is it to rotate the blade manually? If it's hard to do this, then you need to do a thorough maintenance/cleaning and lubricating according to manufacturers instructions.