Waste Oil Heater Forum - Your definitive source for burning waste oil for heat.

Hello I am new to the forum, glad to be here.  I have used a clean burn cb-90-aa with a CB-90-hs burner for three seasons now with good luck.  I wanted to switch to hot water heat, so found an old US Radiator Cast Iron Boiler.  I made all the adapter plates and necessary conections.  I fired the boiler for the first time last weekend and worked great(for a while) brought the water temp up to 180deg nicely.  After a few hours run time I noticed oil seeping out of the gasket on the burner throat.  On further investigation I found an excessive amount of un burned oil mist in the combustion chamber of the boiler.   I have a glass observation port, and I can see the mist floating down and settling on the floor. When the burner was on the old furnace I ran 1 to 1.5lbs oil pressure and had no problems.  Since the boiler has a much larger combustion chamber I increased pressure to 5lbs.  The flame looks great, plenty of heat, with smokeless combustion, but just large amounts of the un burned oil mist.  I have tried adjusting the compressed air pressure and changing the secondary air on the burner fan, as well as cleaning the nozzle several times with no luck.  The only other change i made is adding a heat exchanger which pre heats the wmo to aprox 160deg just before the burner.  The burner has a 9-5 nozzle, it is the origional one that came with the furnace and has 5,000 odd hours on it  Any help or suggestions would be appreciated. Thanks Bill