Keihen FCR carbys and deep water (4 Stroke +Yamaha Wr , +KTM and +Suzuki Drz 400)
The vent hoses on the Keihen FCR carbys all hang down below the frame.
When you do a lot of water crossings and submerges, the vent hoses create an air lock and the bike then stalls during a deep crossing.
To fix the problem and ensure hassle-free water crossings where the vent hoses leave the carby on either side they tee off with a black tee and both hoses run down past the swing arm. Remove the tank and get one hose from either side and run them up along the frame rail under the tank and then hang them pointing down. (You may need to trim them a little.) Tuck them inside the zip ties already there. Replace the tank and the job’s done. Alternatively, you can place them inside the air box.