The default port configuration is stored in the webhcat-site.xml file. To change the default port, you will have to make changes in this file. In the webhcat-site.xml file, change the port 50111 with the port that you want to be the default port.
<configuration>
<property>
<name>templeton.port</name>
<value>50111</value>
<description>The HTTP port for the main server.</description>
</property>
</configuration>