Hot day hunting

摘要

After about 30 minutes use on a hot day I realised that my BMC 1.8 engine was 'hunting' up and down by about 100rpm. When I completed my journey and lifted the deck, the engine bay seemed to have fumes in it. The boat and engine are ten years old, have been regularly serviced and not overused. Do you have any suggestions?rnTo solve this we need to know more about the speed variation. If it was going up and down at about 15-minute intervals, I suspect you might have been seeing the effects of an advanced alternator controller putting the load on the alternatorrnup and down. If it was every few seconds, then you need to first check the drive belt for tension.