100s of hours go by riding, testing, learning and enjoying the experience of motorcycling. This lead to a deeper mechanical knowledge and respect for the complex systems influencing any combustion engine.
The original carburettor (a device for metering air & fuel for combustion) for this engine was designed to harmonise the characteristics of this particular engine. The motorcycle was designed as a road biased off-road capable product, known as a Trail style motorcycle.
This engine was designed to make maximum Torque from 6,200 up to 8,500 RPM. This RPM range makes the engine very useable for daily use and under stressed for longevity, however not very exciting in power delivery.
Carburettor size and it's ability to scavenge air greatly influences the characteristic of the engine and the riding experience.
A series of Carburettors from 30mm to 36mm bore size. Smallest most efficient and responsive at lower RPMs and the biggest only suited to a Wide Open Throttle application.
All carburettors were rebuilt and setup back to back for comparison notes as the character of the engine and exhaust design could change dramatically between versions.
Due to the tightly packaged nature of this motorcycle larger carburettors are not able to make use of the original molded manifolds. So this lead to custom parts being designed.
Profile sections began in card for prototyping to help design the inlet tracts used by the carburettor
These measurement could then be put into CAD where a series of sectioned or low fidelity prototypes were 3D Printed to verify the packaging in 3D.
Moving into the final iteration required confirming the design in a new material. The final version would be printed with a TPU Filament chosen for it's Chemical resistance properties and appropriate Shore Hardness just like it came from the factory.
Final 3D Print version
Left - OEM Part designed with a much smaller flange for original carburettor. Right - Final custom design suited for larger Carburettor
