There are multiple ways to change the screensaver timeout. This way should work on the K4: http://www.mobileread.com/forums/sho....php?p=2130990
Other methods are shown earlier in that thread.
Also, because every K5 has a touchscreen and every K4 does NOT have a touchscreen, there is no need to add "non-touch" or "NT" after K4. That confusion started when the K4 and K5 were released at almost the same time and there was speculation that K5 was running version 4 firmware so the NT was used to (unnecessarily) distinguish the K4 and K5 from each other.