Lean Burn is a patented Suzuki technology which aims to optimize and reduce both fuel consumption and costs.
“It’s a very advanced technology – Suzuki Technical Staff Coordinator Marco Massola explained us during our encounter at NauticStore, a Suzuki dealership based in Genola, Italy – which delivers, under specific conditions, a better air/fuel ratio and greater fuel savings”.
As we know, fuel combustion needs a specific amount of air. This air/fuel ratio, called stoichiometric ratio, is equal to 14.7:1, which means 14.7 parts of oxygen to every single part of fuel. Lean Burn system control changes this ratio to the benefit of lower consumption.
The process is controlled by a central electronic unit. 
When the engine works under stable conditions, which means a cruising situation with no accelerations or decelerations, the control unit changes the stoichiometric fuel air ratio from 14.7:1 to 17:1, making the air/fuel mixture leaner and increasing the parts of oxygen.
The greater amount of air would compromise real engine performances. However, the control unit monitors all engine parameters and doesn’t change engine performances under stable conditions.
Meanwhile, the greater supply of air significantly reduces fuel consumption.
On Suzuki outboards (Suzuki applies Lean Burn technology on most of its range, from 9.9 to 300 HP) fuel saving can be estimated at about 14% under cruising conditions.
Of course, Lean Burn doesn’t get active at the top of the rev range, when we want to experience the best of engine performances, and at the minimum speed. In all intermediate stages, unless we change the gas throttle position, Lean Burn is active.
Suzuki has been extending the use of this technology over its whole range for some years.
However, it can be applied on old-generation Suzuki engines. Learn Burn management is, in fact, entirely carried out by the central unit and only modern devices have a computing capacity sufficient to support the complex work of Lean Burn.
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