diff --git a/moto/rds2/models.py b/moto/rds2/models.py
index 6ae0c98a0..d9c1483ca 100644
--- a/moto/rds2/models.py
+++ b/moto/rds2/models.py
@@ -733,32 +733,27 @@ class RDS2Backend(BaseBackend):
         database = self.describe_databases(db_instance_identifier)[0]
         return database
 
-    def _check_can_stop_rds_instance_(self, database=None):
+    def stop_database(self, db_instance_identifier, db_snapshot_identifier=None):
+        database = self.describe_databases(db_instance_identifier)[0]
         # todo: certain rds types not allowed to be stopped at this time.
-        if database:
-            if database.is_replica or database.multi_az:
+        if database.is_replica or database.multi_az:
                 # should be 400 error
                 return RDSClientError('InvalidDBClusterStateFault', 'Invalid DB type, when trying to perform StopDBInstance. See AWS RDS documentation on rds.stop_db_instance')
-        return True
-
-    def stop_database(self, db_instance_identifier, snapshot_name=None):
-        database = self.describe_databases(db_instance_identifier)[0]
-        self._check_can_stop_rds_instance_(database)
         if database.status != 'available':
-            return RDSClientError('InvalidDBInstanceState', 'when calling the StopDBInstance operation: Instance testdb is not in available state')
-        self.create_rds_snapshot(db_instance_identifier, db_instance_identifier)
+            return RDSClientError('InvalidDBInstanceState', 'when calling the StopDBInstance operation: Instance %s is not in available state' % db_instance_identifier)
+        self.create_rds_snapshot(db_instance_identifier, db_snapshot_identifier)
         database.status = 'shutdown'
         return database
 
     def start_database(self, db_instance_identifier):
         database = self.describe_databases(db_instance_identifier)[0]
-        if database.status != 'shutdown':
-            # should be 400 error
-            return RDSClientError('InvalidDBInstanceState', 'when calling the StartDBInstance operation: Instance {} is not stopped, it cannot be started.' % db_instance_identifier)
+        if database.status != 'shutdown':  # should be 400 error
+            return RDSClientError('InvalidDBInstanceState', 'when calling the StartDBInstance operation: Instance %s is not stopped, it cannot be started.' % db_instance_identifier)
         database.status = 'available'
         return
 
     def create_rds_snapshot(self, db_instance_identifier, db_snapshot_identifier):
+        database = self.describe_databases(db_instance_identifier)[0]
         # todo
         # DBSnapshotAlreadyExists
         # SnapshotQuotaExceeded