http://www.ysengines.net/manuals-dow.../FZ110-YSP.pdf

the 1.10 wieghs the same as the 1.15, (730 grams = 25.75 ounces)

YS manuals give the weight of engine only with no exhaust system
(but with prop nuts and washer)

Example of YS manual weight accuracy: my DZ-170 weighs 957 grams on our FANCY digital scale,
and the manual says 955 grams. - seems like 2 grams of assembly oil was used to me

Either your scale is wrong, or your weighing your 1.10 with a muffler on it or something.