How long does it take for a full carb to completely evaporate?
Late to the game, I wanted to make a few comments about all I have read
Your question is a good one, and I don't know. But I wanted to mention that the problem can happen with a full carburetor.
I have done carb work for years on a variety of carbs..and the WORST are old motorcycles and old tractors that have the fuel gravity flow from the tank. As some of the fuel evaporates, it is replenished, and this continues until no more fuel is left. (Although frequently in this process, the float eventually sticks either open or closed.)
So, we are not talking about the solids of a bowl, or a partial bowl, but a partial or entire tank in many cases. It is a horrible carb job to do.
Idle jets are tiny. Many carbs have filter screens so tiny in mesh, that a particle cannot get through which would clog the jet. Yet..I see clogged jets frequently, so there can be no doubt how this happens. It is coming through in a liquid state, and then solids are being formed in the bowl. And it need not be an evaporation issue, but can also be an oxidation issue where oxygen attaches making new compounds. Products like Stabil are mostly anti-oxidants.
Shellac was mentioned, and is a product of the Lac bug, and is an excellent insulator. Most folks call what in in the bowls of carbs "varnish" in these parts, but I also hear gum sometimes. (Not trying to be a stickler...just looking for a way to tell folks about handy bug secretions.)
Shellac - Wikipedia, the free encyclopedia
And it really is the "She" lac. Apparently the "he" lac only helps us by propagating more "shes"
(Incidentally, that's one of the best things many of you ever did for the world too.
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two cycles...frequently these are protected by: the lube oil additive is also a fuel stabilizer. Also, very little of the fuel is exposed to open air, and fuel does not gravity flow into the carb. The 2-cycle carb has its own built-in fuel pump driven by crankcase pressure oscillations. So 2 cycle fuel has stabilizers by default, and the fuel pump is in the carb, so small evaporation will not be replenished by gravity flow.
When I purchase a device with a 2 cycle, I insist on those with the little push bulb (primer bulb.) The bulb is not a primer of the engine, but instead a primer of the fuel pump. If you dump all the fuel out, and then use the primer, you frequently can replace that fuel with air (perhaps not on all motors, but my Husqavarna blower suggests that as part of the "prepare for storage" procedure.)
When I want to put away a 2 cycle for the season: I start it up and run it until it is warm so it will restart easily. Then I empty all the fuel out of the fuel tank through a funnel back to a small storage tank...pause long enough to push the primer bulb to pump (instead of fuel now) air through the works. Drain the fuel that returned during this pumping, and then put the cap on. Crank the engine, and let it run until it stops. This all serves to get as much fuel out as possible, and even protects the tiny pores in the fuel filter (in the tank) from getting clogged.
Looking at the Stabil site, their ethanol 411 links, it seems myths are growing about ethanol.
BoatUS Magazine: Three Ethanol Myths Clarified
Anyway, this was too long to read, but if you did so, accept my apology.
Bonus:
Coercivity - Wikipedia, the free encyclopedia
On the coercivity page, you get the see an example of magnetic hysteresis curves. Without magnetic hysteresis, the chart would look like a straight line with a certain slope. But, without magnetic hysteresis, a brushless alternator likely would never have been invented since it would have had to be flashed each time, or a battery would have to be installed.
Don't be mad...it was a bonus. Don't blame me for your hysteresis, you weren't even coerced!
