The Saito 150 (and by extension the 120 and 180) have the same mounting hole arrangement (hols spacing and crank case width) as the YS 140's. BUT bear in mind two things - firstly, the Saito's have a web coming forwards from the mounting lug. Depending on the type of mount this may or may not interfere. Secondly, the Saito is a different length (can't remeber for sure whether it is slightly longer or shorter, it's a couple of years since I replaced my Saito with a YS so can't recall exactly which way I had to move the mounting holes), I think it is shorter though.

These should not be of much concern when installing from scratch but may need to be considered if swapped from YS to Saito or vice-versa.

James