Owned by one of our regular customers, who’s lucky enough to keep a fleet of really nice Italian bikes in his garage, this 8 valve Moto Guzzi Griso was in for a complete custom remap to its Marelli ECU. It’s wearing open cans but was running poorly, especially off the bottom; and it’s the same old problem, the lambda sensors mess up both the on/off throttle fuelling and idle.
This took time to sort – more so than a Ducati, for instance – but the result was well worth the effort. First job was to plug into the ECU and switch off the lambdas completely, as they were essentially interfering in proceedings plus their processing power was simply to slow to be of any use. The fuelling was incredibly lean at the bottom – horrible, in fact – so adding more fuel here smoothed it all out beautifully. As a byproduct of the remapping, the engine gained power; it came in making 102bhp and left with 111bhp but, more importantly, the 9bhp boost was throughout the entire rev range.
Open cans matched to stock lambda sensors make for rough running low down...
...but switching the lambdas off and remapping sorted the bottom end and gave a 9bhp boost everywhere. Can't be bad!
