Sermis,you may want to check your fuel cut-off mechanism on the IP.
The shut-off handle on the dash doesn't actually attach to the lever (shown in the images below), it only engages it and when the handle is pushed back in on the dash, the lever must be free enough to return to starting=open position.
To check, remove the cover, only two screws and the control cable comes with it. Nothing can go wrong here, simple procedure, just don't lose the screws or damage the gasket.
When the lever is exposed, move it back to "stop" position and make sure it returns to full open position on its own when you let it go.
If it doesn't return right away, then the fuel is cut off to some extent and that would explain the hard starting. Continued cranking may jar it and move it to the open position, but it must be free enough to do it on its own.
I'm messing with mine on the LDS465-2 engine and it's a bit slow returning to open position having been left without a cover for years.
I'm using brake cleaner to get the gummy old oil off and relubing it.
The linkage (fuel control rod) goes to the fulcrum assy below the fuel density compensator and if mine doesn't loosen up satisfactorily, I'll have to remove the FDC and check the operation of the linkage below it. I may do that in any case, just to be sure.