Topic: Weird color residue----------gas ???

[MikeJW]

I know this is not very important or technical, but I would like to know. Just finished taking my carbs apart for cleaning & checking and I noticed in every float bowl there was a faint yellow stain inside them. Also, the floats had that yellow stain on them. Not all over, just in certain places. Carb cleaner would remove most of it, but not all. Do ya'll think that might be from all the ethanol they are putting in our gas ?  I doubt it (the yellow) is hurting anything, but I just wondered. Anyone care to comment ?                        Thanks
Mike in Memphis

[flybox1]

well, i think it is, or can lead to technical things...
its the varnish from your gas sitting.  what you're seeing is not hurting any thing now, but if left to build up, it can clog your jets and cause all sorts of foul runnings.
many chose to use a fuel additive/stabilizer if a bike is to sit for a while.
chosing to drain gas from bowls before storage is always a good idea.
I use seafoam in my gas and ride regularly.
helps to cut down on this yellow varnish buildup and keep carb bits/fuel system clean.

[MikeJW]

You could be right, flybox. Over the years, I've seen the varnish thing in gas after it has been sitting and it's kind of brownish or an amber color. This I'm talking about is pale yellow and it actually made a stain on the float. Not the metal but the black part that floats. I ride pretty regularly and use Seafoam about every other time I fill up.
Mike

[flybox1]

got a picture of it?   
i dont know that i've experienced this....yet.

[MikeJW]

No, sorry. I put everything back together before I got on the computer. It was on the inside walls of the float bowls and 1-2 sides of the actual floats. My floats are not hollow. They are solid..some sort of black fiber material. I cleaned about 95% of it off, scrubbing real hard with carb cleaner. Think of an old, faded yellow Post-It note. That's the color.
Mike

[flybox1]

no prob.  got the same material floats on my 350F.
weird that it appears WITH your use of seafoam. 
maybe the fuel/chemistry experts here will enlighten us 

i guess if it has the ability to come off and become lodged somewhere, impeding fuel flow, it cant be good, and should be removed.

[BobbyR]

In almost all carbs you may find a yellowish film. Much of it is the result of the fuel evaporating and deposting a film. As was said before this film will thicken over time and cause clogging. Good solvents like Seafoam and Techtron dissolve it and carry it through the carbs as you ride. The now banned MBTE left a whitish deposit on the emulsion tubes which does not want to dissoleve.  

[MikeJW]

I really appreciate everyone's comments. Just to make sure I'm making myself perfectly clear, however, let me say again. This is Not really a deposit, as one usually thinks of such. It is a stain. More like if you accidentally spilled some wood furniture stain on your hand or stain from handling green walnuts. Plus, I didn't see it on any of the brass parts. Just the pot metal float bowls and the fiber floats and it wasn't everywhere on them.
Mike