Bigger 350 cc Cylinder
I was going through possibility of making the 313 cc cylinder to bigger one and BMW's 350 cc scooter the C400X felt like direct fit but I am not sure on it's construction to accommodate the water jacket, plumbing, crank rod length etc.
The bore is same in both engines at 80 mm only stroke is longer on 350 cc engine at 69.6 mm against 313 cc engines 62.1 mm, so this 7.5 mm adds extra 37 cc, the power figure is same but it comes as early as 7500 RPM against g310's 9500 rpm.
Worth considering if it needs only the cylinder kit replacement with timing chain, longer crank and few small bits here n there.
Members having access to c400x engine physically or over the net do share more info on the same. I am sure this mod is going to sort out those issues of bike lagging the power and shutting down at low speeds.
Triumph Tiger 800 XCX 2016