The “Yoshimura” is a 1987 Suzuki GSX-R1100 “slabside” restomod built by Yohann Kostrzewa of the French workshop KOS’THOR. Inspired by the legendary 24-hour endurance racers that dominated the Suzuka circuit in the 1990s, the build is a tribute to the legacy of Hideo “Pops” Yoshimura.
The project began with a neglected donor bike that was completely stripped and rebuilt to recreate the look and feel of a factory-fresh racing machine.
A Truly Special Custom Suzuki GSX-R1100
Mechanically, the bike has been significantly uprated to back up its aggressive aesthetic. The heart of the machine is a 1216cc big-bore engine featuring Wiseco forged pistons and high-performance endurance camshafts.
It breathes through Mikuni RS40 flat-slide carburetors—known for their distinctive mechanical clicking at idle—and exhales through a custom exhaust system that pairs a Devil 4-into-1 manifold with an iconic Yoshimura Tri-Oval silencer. These modifications result in a formidable output of approximately 160 horsepower.
Visually, the motorcycle is defined by its striking red and black Yoshimura livery, applied over a modified and reinforced Ricambi racing fairing. To complete the period-correct endurance look, Kostrzewa added a yellow-tinted headlight and a digital Yoshimura multi-temp meter to monitor the oil-cooled engine.
The chassis is sharpened for modern riding with a YSS rear shock and R6 rearsets, resulting in a machine that Kostrzewa describes as feeling exactly like a professional racing bike from the 1990s.
