We’re starting with this FAQ – and it’s in the top 3 – because we know the answer. YES! Most bikes are snatchy because from 2006 the EURO 3 emission rules were introduced, and any new model had to conform so ended up loaded with lambda sensors, airbox flaps, exhaust valves and a secondary air system. In essence, mostly a lot of cheating to get round the exhaust gas and noise issues…
In a lot of cases, especially older engines that weren’t designed to work with all the extra interference, this is the cause of all the running issues. In 2016 EURO 4 came a long (did you notice a lot of model changes in 2011/12? That’s older spec engines being pushed out) and these newer designs have an extra control; Fly-By-Wire throttles. The manufacturers are trying to run engines much leaner, toward the total combustion 14.7 stoichiometric ratio and the FBW throttle gives them the control of how the fuelling is delivered – not the rider.
So whatever the rider demands, the ECU only gives what it wants to. The effect is twofold; as well as managing fuel it’s also trying to make the engine more efficient, because its been made so inefficient to get it through the test. Rider modes come into play here – these are rider aids and options, but without ’em one single engine setting would not only be a massive compromise to performance, the bike would also be unable to pass Euro 4.
The manufacturers know how to turn out engines that make great power and go like stink – but most of what they bolt around them is to get them through testing. Thus the part throttle running issues, which we can at least sort via the ECU.