The link above is rather outdated. For WebLogic 12c you may define the transaction timout in a transaction-descriptor for each EJB in the WebLogic deployment descriptor weblogic-ejb-jar.xml, see weblogic-ejb-jar.xml Deployment Descriptor Reference.
For a message driven been it looks like this:
<weblogic-enterprise-bean>
<ejb-name>TestMessageBeanLow</ejb-name>
<message-driven-descriptor>
<pool>
<max-beans-in-free-pool>1</max-beans-in-free-pool>
</pool>
<destination-jndi-name>jms/ActiveMQ/TestRequestQueue_LOW</destination-jndi-name>
<connection-factory-jndi-name>jms/ActiveMQ/TestConnectionFactory</connection-factory-jndi-name>
</message-driven-descriptor>
<transaction-descriptor>
<trans-timeout-seconds>60</trans-timeout-seconds>
</transaction-descriptor>
<resource-description>
<res-ref-name>jms/ConnectionFactory</res-ref-name>
<jndi-name>jms/ActiveMQ/TestConnectionFactory</jndi-name>
</resource-description>
</weblogic-enterprise-bean>