White gunge in float bowl

After a 2 or 3 week holiday my Commando wouldn't start. Not a peep when kicking. Spark was there. Always started first or second kick. I decided today to take the carbs apart and found plenty white gunge in the bowls. I am wondering if this is the result of only 2 weeks holiday with modern petrol sitting in the carbs, or is there perhaps something going on in the petrol tank (haven't checked the petcock filters yet).

I also haven't put it back together yet as need new gaskets, but I am quite shocked to see this crap after only 2 or 3 weeks.

More information is needed.

Fiberglass tank?

Coated tank?

Is ethanol being blended into pump gas there?

I've seen the white goop in automotive, boat, and motorcycle carburetors that sat longer than 3 weeks. Unfortunately, I didn't do anything other than clean it out. I did not perform any scientific analysis. I just wanted to start the engines. If the bowl dries out for a few months I think that goop turns into a powder, but am not 100% sure. I have no clue what causes it. My gut says it could be a bad batch of pump gas, or some voodoo electrolysis. I have not seen that white goop again in a carburetor for maybe 45 years.

My Norton sits for most of the winter months. I do start it and run it at about 2000 RPM for 15 minutes every couple of weeks with old gas in the tank. I use Stabil, but plan to also try some of the Ethanol Shield to see if it helps with the pin head size drops of water I see in the fuel when I drain the bowls.

concours said:

More information is needed.

Fiberglass tank?

Coated tank?

Is ethanol being blended into pump gas there?

Click to expand...

Metal tank, coated, though I don't know what with. Yes, I believe ethanol is added here - there is either E5 or E10 and I never know which to use. Sometimes it is labelled Super 95 and Super Plus 98 ROZ.

GraemeH said:

Metal tank, coated, though I don't know what with. Yes, I believe ethanol is added here - there is either E5 or E10 and I never know which to use. Sometimes it is labelled Super 95 and Super Plus 98 ROZ.

Click to expand...

Ethanol dissolving the old coating.

I'm dealing with this now. My tank is the original steel Roadster tank but I coated it some years ago. The problem is that I don't remember what I coated it with. Now my carb slide locks up if left for a couple of months. It seems that whatever I lined the tank with is now dissolving, coating the slide of the carb (I'm running a single carb) and locking up the carb slide. I'd like to remove whatever I have in the tank but don't want to lose the beautiful paint. Contemplating...

I emptied the tank today and took out the petcocks. There was nothing on the petcock filters other than small flakes of whatever, certainly no white gunge. So I guess once it sits in the carb bowls it precipitates out or something.

I have a metal fuel tank coated with the dreaded doom and gloom sky is falling Kreem coating. I use E10 and have not seen that goop in a carburetor bowl in the 30+ years I've been using the Kreem coated fuel tank. I've used Amal, Mikuni, and Keihin carburetors with the same fuel tank. The Kreem coating in my tank doesn't dissolve with pump gas as far as I can tell, and I leave fuel in the tank for months on end.

I currently don't let my fuel bowls dry out completely. I turn the petcocks to the open position at least once a week if I remember, and as mentioned start the engine and run it for a minimum of 15 minutes a couple times a month during the cold wet months. I don't know if any of that does any good, but it doesn't hurt anything.