Alastair Seeley completed a disappointing British Supersport weekend by finishing fifth in Sunday's feature race at Knockhill in Scotland.
The Carrickfergus rider, who was sixth in Saturday's sprint race, is 50 points adrift of leader Billy McConnell, who was second behind Luke Mossey.
Seeley was at the back of the lead group throughout the 26-lap race on the Scottish circuit.
Fellow Carrick man Glenn Irwin is fifth in the series after coming in seventh.
Seeley remains third although he is joined on 102 points by Luke Stapleford, who completed the podium places on Sunday.
"We struggled with the same problem in both races this weekend with the bike backing into the final turn," said Mar-Train rider Seeley.
"While others enjoy that style of riding, I prefer a more in-line set-up on corner entry, which left me struggling both on corner entry and corner exit.
"I was also struggling to get the bike off the line this weekend, but that's racing.
"There's no doubting the speed of the Mar-Train Racing R6 and the strength of the package - we just need to make the most of it at Brands in a few weeks time and get back into the championship mix."
Meanwhile, Jordanstown's Andy Reid won the National Superstock 600cc race and is now 36 points clear in the standings.