After a flying fourth in morning practice, an increase in track temperature caused set-up problems for Monster Yamaha Tech 3's Colin Edwards at Phillip Island on Friday.
The Texan dropped to ninth in the afternoon as a result - but his morning time kept him fourth overall, one-second from Casey Stoner (Honda) on the combined timesheets. Of the three riders ahead of him, only Marco Simoncelli (third) improved in FP2.
“This morning went brilliantly and I came out of the gate really fast and flying," said Edwards. "I felt good on the bike but this afternoon I just couldn't get close to the pace I had this morning.
"I had really good grip from the front tyre this morning, but when the temperature started to come up a little bit the track started to feel a bit greasy.
"So for this afternoon we switched to the hard compound front tyre to see what the difference was and there is a really fine line between what does and doesn't work around this track.
"We made one little change to the bike but the bike became really hard to ride. The track is pretty bumpy and I was having a lot of vibration and I just didn't feel anywhere near as comfortable in the second session as I did this morning.
"We need to go back to what we know worked this morning and make a couple of tweaks to see if we can make that set-up better. The main thing is to get the front working better over the bumps.”
Rookie team-mate Cal Crutchlow finished twelfth on combined times with a best lap time 0.494sec from Edwards.
Unlike many tracks this year, Crutchlow has raced at Phillip Island before (in WSBK) but he also has plenty of set-up work to do.
“Today's result doesn't look too bad on the timesheets because although I am down in twelfth, I am less than half-a-second away from Colin and he is fourth," said Crutchlow.
"But it was a very difficult day to be honest because I had a lot of grip issues and the bike was hard to turn as well. And if I run over any rough tarmac or any bumps I nearly crash, so I've got to sit down with my guys tonight and come up with a plan to try and make the bike better for tomorrow."