i have been bobbing a xs650 iliteraly found in the weeds of an old farmer, got it for a little of nothing, it was missing bars/mounts, tank, seat, and assorted other pieces. it does have compression. i am done w/ most of the fab work, and have it looking cool, am wiring it but cant get spark so am thinking ill get electronics from pete. but think maybe i had better figure out the year of this beast. sn is 2fo-157344 think maybe it is a 78-79 but would like to know better. please advise