" I have an unusual problem wi
" I have an unusual problem with a Bukh DV20 marine engine - the engine periodically & without warning will "run away" ie; reach destructive speeds from a low idle speed setting to 4000+ rpm leading to destructive engine damage. This has happened on 2 occasions & on both occurences the engine had been idling under a no-load condition @ approximately 1000 rpm.The engine had to be reconditioned after the first event as it dropped an exhaust valve @ destroyed the piston, damaged the head,etc.While the engine was out of the boat I thoroughly inspected the governor & could find no evidence of a problem @ all.The fuel injection pump & injectors were both reconditioned & calibrated & the governor was set for correct low speed settings as per the manual, on the engine test stand subsequent to the overhaul.The engine starts & runs flawlessly under all conditions & even when it runs away it shows no sign of excess smoke on the exhaust. It doesn't burn oil & the oil is changed @ 50 hr intervals, using SAE 15w40 CG4 classification oil.I am an experienced diesel engine mechanic with 28 years of experience in the heavy equipment & marine industries & admit that this one has me baffled. I have even considered the possibility that the engine is running away on it's own crankcase fumes but can find no evidence to support this theory.I did once encounter a precombustion chamber that ran away with a stuck fuel injector as the fuel @ transfer pump pressure was entering the precombustion chamber & burning uncontrolled-the governor cannot regulate what it does not deliver. If anyone can share their thoughts on what might be wrong here I would be most appreciative. "
" I have an unusual problem with a Bukh DV20 marine engine - the engine periodically & without warning will "run away" ie; reach destructive speeds from a low idle speed setting to 4000+ rpm leading to destructive engine damage. This has happened on 2 occasions & on both occurences the engine had been idling under a no-load condition @ approximately 1000 rpm.The engine had to be reconditioned after the first event as it dropped an exhaust valve @ destroyed the piston, damaged the head,etc.While the engine was out of the boat I thoroughly inspected the governor & could find no evidence of a problem @ all.The fuel injection pump & injectors were both reconditioned & calibrated & the governor was set for correct low speed settings as per the manual, on the engine test stand subsequent to the overhaul.The engine starts & runs flawlessly under all conditions & even when it runs away it shows no sign of excess smoke on the exhaust. It doesn't burn oil & the oil is changed @ 50 hr intervals, using SAE 15w40 CG4 classification oil.I am an experienced diesel engine mechanic with 28 years of experience in the heavy equipment & marine industries & admit that this one has me baffled. I have even considered the possibility that the engine is running away on it's own crankcase fumes but can find no evidence to support this theory.I did once encounter a precombustion chamber that ran away with a stuck fuel injector as the fuel @ transfer pump pressure was entering the precombustion chamber & burning uncontrolled-the governor cannot regulate what it does not deliver. If anyone can share their thoughts on what might be wrong here I would be most appreciative. "