2009 Yamaha F40 Outboard Service Manual, Page 183Get this manual
Power unit 8Turn the flywheel magnet an additional 240 clockwise and align the" mark on the driven sprocket with the" mark on the cylinder head
6Measure each valve clearance and following the step 7step 12
9Measure the intake and exhaust valve clearances of the corresponding cylinder#1 #2 #3 IN EX : Not applicable 10Turn the flywheel magnet an additional 240 clockwise and align the" mark on the driven sprocket with the" mark on the cylinder head