blade 11 is provided with a horizontal mounting rib 17 that is received in a groove 18 in a casting that comprises a lower exciter housing 20 the front of the blade 11 also includes an upper horizontal mounting rib 21 over which a pair of mounting clips 22 are attached to the housing 20 with machine screws 23 to clamp the blade 11 to the exciter housing 20 referring also to fig2 the engine 13 is mounted vertically above and directly to the exciter housing 20 and includes a direct driving connection between the engine drive shaft not shown and an eccentric exciter mechanism mounted within the housing 20 via a flexible elastomer coupling 24 the flexible coupling 24 is enclosed in an engine output shaft housing 25 attached to the engine and overlying the exciter housing the engine output shaft housing also enclosing three elastomer shock absorbers 26 equally spaced around the flexible coupling 24 the shock absorbers 26 interconnect the engine output shaft housing 25 and the exciter housing 20 each of the shock absorbers 26 is attached at its lower end to a coupling surface 27 on the exciter housing 20 and at its upper end to the engine output shaft housing 25 with machine screws 28 as shown in fig1 in the assembled position the interface between the exciter housing 20 and the clutch housing 25 is sealed with an annular seal 30 the direct driving connection between the engine 13 and the exciter mechanism 12 eliminates the need for a gear box or transmission and also helps isolate the transmission of vibrations from the engine to the operator handle.