Timeout systemctl systemd

systemctl cat

Then you need to create a {service}.service file to override your settings with information from [Service] section from systemctl cat {service} command and restart daemon after that:

echo "[Service]
TimeoutSec=15min
ExecStart=/etc/rc.d/init.d/ start
ExecStop=/etc/rc.d/init.d/ stop
ExecReload=/etc/rc.d/init.d/ reload" > /lib/systemd/system/{service}.service

sudo systemctl daemon-reload

Timeout set by systemd

systemctl show SERVICE_NAME.service -p TimeoutStopUSec