Scudrunners

I started taking carburetors apart (on motorcycles, cars,
boats and airplanes) when I was less than 10 years old.

Despite what TC might tell you, they are very very simple.

There is a float that goes up and down in the float bowl,
and it's usual failure mode is to sink.

The float is like a teeter-totter - at the other end, it raises
and lowers needles into a seat.

[img width=348 height=500]https://www.fix.com/assets/content/1544 ... ght-02.png[/img]

Common failure mode is that the needle and seat gums up
with residue (eg from mogas) and sticks.

You can tap a carburetor on the side with the handle of a
screwdriver to try to free a stuck float.  Or you can use some
Seafoam which is a solvent and dissolves the gum in your
carb.  Be careful using any solvent in your airplane because
it has much shittier seals and gaskets than your $99 lawn
mower.  I have seen guys pour a gallon of lacquer thinner -
a very nasty solvent indeed - into their car gas tank, to try
to dissolve deposits in their fuel system.  Not recommended
in a typical shitty piston certified aircraft.

Harrison Ford had a very expensive overhaul of his carburetor
by a shop with very fancy paper and they fucked it up and
he damn near died when his PT-22 Ryan was force-landed.

It was wrecked and he was injured, and the cause of the
accident was completely faulty maintenance, by a shop with
very nice paper.

Try to learn a lesson from that.  Your carburetor cannot read
and does not give a shit about paper.  Make it work correctly.

A carburetor is not much more complicated than your toilet.

As a pilot, you should have the intellectual capability to grasp
the functioning of both a carburetor and a toilet.

Thanks for the info.


Mogas with ethanol(which is most except perhaps Shell 92 octane V-Power) can also cause the shellac covering the cork float in certain old carbs to bubble due to reaction. Then the pieces can fall off and block stuff.

[quote author=JW Scud link=topic=8468.msg23371#msg23371 date=1526920952]
Thanks for the info.


Mogas with ethanol(which is most except perhaps Shell 92 octane V-Power) can also cause the shellac covering the cork float in certain old carbs to bubble due to reaction. Then the pieces can fall off and block stuff.
[/quote]


[url=https://www.pure-gas.org/]https://www.pure-gas.org/[/url]


I generally pick up fuel for the boat at Canadian Tire. Ethanol free, cheapest in the area and CT money.

Alcohol is really bad shit, and most of the time, buying premium
mogas will avoid it.  On the upside, nobody's gas lines freeze up
in the cars any more, but it's really hard on the fuel system.

If your needle valve/seat is dribbling, turn the [b]FUEL SELECTOR[/b] to
[b]OFF[/b] when you shut the engine off.  This works on airplanes
and motorcycles from the 20th century, until you get around to
cleaning the needle valve and seat.

It's like learning to do wheel landings when your tailwheel is shimmying.

I disagree with "Don't worry about it guy. Carburetors are simple. Do it yourself." you who wrote the title.

I agree heartily with "Find someone good with Carburetors to rebuild them."

I'm pretty decent with a wrench but for some reason don't get along with Rochesters, unless I get it rebuilt by someone else. I can install it and set the mixture but if I take it apart then change out some parts it won't work as well. I know it's a matter of practice but I'm not there.