John Hopkins made his debut with Samsung Crescent Suzuki during the start of the Cartagena BSB test in Spain on Thursday.
Hopkins, whose fortunes went downhill after finishing fourth in the 2007 MotoGP World Championship with Rizla Suzuki, intends to use BSB to re-launch his international career this season.
"We've had a really good, productive first day,” said Hopper, who has raced 1000cc production machinery in WSBK and then AMA in recent years.
“The base-settings we started with were good and I quickly felt comfortable with the bike.
“Actually, after five months off a road racer I'll confess I was ready to stick my leg out on the corners like I do on my dirt bike, so I probably looked a bit awkward for that first session.
“But I quickly adapted and even in the second session I was starting to chip-away at the settings.
"It was a solid first day; I think we can say we nailed it. I feel really comfortable on the bike and I'm looking forward to getting up-to-speed and seeing what's to be done then."
The American will be joined in the Crescent team by Jon Kirkham, who is also on track in Spain.
"Coming from a Superstock machine, there's so much to take in; things I've not used before - like the electronics package,” admitted Kirkham. “And these bikes aren't as forgiving as a Superstock, so I worked on keeping smooth and staying composed.
"I tried not to think about lap times but after I got a good lap in session three, I couldn't help myself. But it's not about times right now; the speed will come and it's a long season - and this is just the first day! I'm really pleased with how it's all gone."
Crescent didn't release any lap times.