There will be no default model paramaters without

the minimum model line:
J1 a b c JM1
.model JM1 njf

src/spicelib/parser/inpgmod.c

@@ -334,7 +334,7 @@ INPgetMod(CKTcircuit *ckt, char *name, INPmodel **model, INPtables *tab)
 #endif
 
     *model = NULL;
-    return tprintf("Unable to find definition of model %s - default assumed\n", name);
+    return tprintf("Unable to find definition of model %s\n", name);
 }