Hey Terry! I see you got your carb torn down and found a white powdery substance in the emulsion well. In my experience, this is aluminum oxide and most commonly produced from the presence of water.
I can't recall if I have, or have not used brake cleaner on carb parts....I typically soak them in dedicated carb cleaner solution. I did a bit of searching and found a claim that allowing brake cleaner to "pool" and remain in contact with aluminum over an extended period can result in white nodules forming. Was there any spraying of carb cleaner into any orifices after it was assembled? Perhaps that could have pooled it up and resulted in some corrosion.
If your fuel contained ethanol, it will accumulate moisture over time. Assuming the fuel had water, I'm not convinced it would corrode the aluminum in such a short eposure time.
The emulsion well fills with fuel to the same height as float level. When the boosters get a strong signal (wide open throttle) for an extended time, the level drops and additional emulsion holes are exposed. Air comes in from the Main Air Bleed and through the emulsion bleeds to aerate fuel as it's pulled into the boosters. The point being, that the emulsion well would be "wetted" with fuel.
As for cleaning, I suggest sticking with carb cleaner. Do not use simple green, Purple Power, or any other caustic cleaners. They will discolor and corrode the bare aluminum. A well known carb builder on facebook recommends a mixture of Totally Awesome and water in an ultrasonic cleaner. I've done this and observed discoloration, so keep the exposure time to a minimum, as Totally Awesome has some caustic properties.
I believe you said you have a fuel filter, so that should rule out this substance coming in with the fuel, but does not rule out the presence of water in the fuel. I suggest the tank is thoroughly cleaned or replaced before you try to run it again. Either that or supply fuel from a gas can via a length of fuel hose from fuel pump into the gas can. The gas cans used with smaller outboard boat engines are good for this purpose (in case you have one available).
Regards,
Brian
I can't recall if I have, or have not used brake cleaner on carb parts....I typically soak them in dedicated carb cleaner solution. I did a bit of searching and found a claim that allowing brake cleaner to "pool" and remain in contact with aluminum over an extended period can result in white nodules forming. Was there any spraying of carb cleaner into any orifices after it was assembled? Perhaps that could have pooled it up and resulted in some corrosion.
If your fuel contained ethanol, it will accumulate moisture over time. Assuming the fuel had water, I'm not convinced it would corrode the aluminum in such a short eposure time.
The emulsion well fills with fuel to the same height as float level. When the boosters get a strong signal (wide open throttle) for an extended time, the level drops and additional emulsion holes are exposed. Air comes in from the Main Air Bleed and through the emulsion bleeds to aerate fuel as it's pulled into the boosters. The point being, that the emulsion well would be "wetted" with fuel.
As for cleaning, I suggest sticking with carb cleaner. Do not use simple green, Purple Power, or any other caustic cleaners. They will discolor and corrode the bare aluminum. A well known carb builder on facebook recommends a mixture of Totally Awesome and water in an ultrasonic cleaner. I've done this and observed discoloration, so keep the exposure time to a minimum, as Totally Awesome has some caustic properties.
I believe you said you have a fuel filter, so that should rule out this substance coming in with the fuel, but does not rule out the presence of water in the fuel. I suggest the tank is thoroughly cleaned or replaced before you try to run it again. Either that or supply fuel from a gas can via a length of fuel hose from fuel pump into the gas can. The gas cans used with smaller outboard boat engines are good for this purpose (in case you have one available).
Regards,
Brian
