yep because it's when it's self propelled it's heavy yeah
( yep ( because ( it ( 's ( when ( ( ( it 's ) self ) ( propelled ( it ( 's ( heavy yeah ) ) ) ) ) ) ) ) ) )
(ROOT (S (VP (VB yep) (SBAR (IN because) (S (NP (PRP it)) (VP (VBZ 's) (SBAR (WHADVP (WRB when)) (S (NP (NP (PRP it) (POS 's)) (NN self)) (VP (VBD propelled) (SBAR (S (NP (PRP it)) (VP (VBZ 's) (NP (JJ heavy) (NN yeah))))))))))))))
it's very light when it's self propelled
( it ( ( 's ( very light ) ) ( when ( ( ( it 's ) self ) propelled ) ) ) )
(ROOT (S (NP (PRP it)) (VP (VBZ 's) (ADJP (RB very) (JJ light)) (SBAR (WHADVP (WRB when)) (S (NP (NP (PRP it) (POS 's)) (NN self)) (VP (VBD propelled)))))))