I have an old Honda B100, 1985 maybe, that runs great at idle with good oil pressure. When I rev it up at about 2000 rpm the oil pressure light starts to fade away. I talked to a Honda mechanic here in Sweden and he told me that it´s a typical old Honda problem with an oil pipe in the bottom of the oilpan thats get clogged with "old oil dirt". Is there some way to remove the dirt without tearing the enginge down completely?<br />Flushing it with something maybe?<br /> 