Motorcycle Repair: Bourget with S&S motor, no oil pressure, smokey mountains, oil system

Question
Good morning: My husband rides a 2005 Bourget with 10.000 miles on it, we've had it for almost 2 yrs.  No problems at all were encountered, even taking it to the Smokey Mountains twice last summer, where the temp. soared to over 100 degrees.  Suddenly, coming back to Florida, the oil pressure dropped to ZERO, the motor started sounding odd.  He immediately took it to the local chopper dealer, which said to clean the oil system (which in this case runs through the entire frame of the bike).  Bourget send a new oil pump (no charge),the mechanic flushed the entire system and said he was good to go.  Within 5 mls. from the shop the oil pressure dropped back to ZERO, the motor started sounding odd & we took the bike back.  
This has happened a total of 4 times now, anywhere from 5 mls. to 40 mls. into a 'roadtrip' the oil pressure drops to ZERO, the motor sounds odd, we shut the bike down and call our trailer to pick it up and trailer it home.  We are at our witts end, no one knows what the problem is - can you help?

Answer
There are only two reasons for no oil pressure. One is a bad pump and the other is no oil getting to the pump. I would look for a blockage int he oil system, or a pinched oil line that is causing the blockage. Since you installed a new oil pump the pump is probably not the problem.
Good luck and happy riding
Mike