In 2006 he took over Franck Montagny’s Super Aguri from German Grand Prix having already appeared as a test driver for the team at four races.
He returned to a test driver role for Super Aguri in 2007, while racing in GP2 for the BCN team.
Yamamoto posted a career-best finish of 12th in the very wet Japanese Grand Prix at Fuji, where team mate Adrian Sutil finished eighth. Yamamoto was not retained for 2008 but moved to Renault as test driver alongside Romain Grosjean.
After being dropped by Renault, Yamamoto sat out 2009 but returned in 2010 as a reserve driver for HRT. At the British Grand Prix he was promoted to the race team in place of Bruno Senna.