Suzuki DF25/DF30 Four Stroke Service Manual, Page 129Get this manual
7-12 POWER UNIT 3Turn the crankshaft in its normal running direction (R direction) until No.1 cylinder reaches top dead center
NOTE: To bring No.1 cylinder top dead center, align mark on the crankshaft with mark on the crank caseNOTE: After timing chain has been removed, do not turn crankshaft or camshaft
a: Match mark on crankcase S: Match mark on crankshaft R: Engine normal running direction