These peeps who crank open the fuel injection pump to get extra power, it's disgraceful , should be an MOT for boats to make sure they are using clean 2 stroke engines.
Actually loads of new diesels are like this - I don't know how they will ever pass an MOT smoke test. Some of the new Audis and VWs I have driven have been like this as was the Mondeo - my old Rover 420 is MUCH cleaner - and my Disco tdi even after I messed with the pump - maybe it's the cooking oil that helps!!!