by Peter Maire
(New Zealand )
Regardless of what boat speed / rpm setting is the rpm and speed with gradually drop and then suddenly surges right back up. For example be 6 knots down to 4 knots or 30 knots down to 20knots.
Mechanical has changed O2 sensor, removed and cleaned injectors. Swapped out ECU and all other suggestions from the NZ importer. Zero improvement.