Hi gravelman, Never having owned or worked on one of this model of Scott Bonnar, I am flying blind here, but I will try and give you some advice.
You see the main difference between the Model 45 and the Diplomat 430 is the cutting set-up and drive train.
In the Model 45, the cylinder reel adjusts to a fixed bottom blade; whereas in the Model 430, the cylinder reel is fixed and the bottom blade adjusts to it.
For this reason the cylinder reel
must be ground perfectly parallel; for it to achieve a correct cutting action, along the entire length of the bedknife (bottom blade)
From looking at the illustrated parts list for this model, I suggest you re-intall your reel assembly, bottom blade assembly and then finely adjust the bedknife to the cylinder reel....Remember the reel has to
almost contact the bedknife, and thus spin freely by hand....the front perpendicular edge of the bedknife and the helix spiral of the sharp reel, is where the cutting action occurs.
Let us know please how you get on.
