i wasn't going to jump in here but the 45 was brought up.i got a MVVS 45 that had need of new crank bearings after 4-5 gals. of fuel.the bearings were BONE DRY there was no way to get any lubrication to them.but the new crankshaft has a lubercation port down the center of shaft that exits in between the bearings now.what i am trying to say is most newly design engines go through a (get the bugs out) early on.
to be fair i also had one of the first da 50's that went back for updates.