I have a few things to translate (not directly business-related) but I'm unsure of the correct expressions used in UK or USA so if you have some insights....

1. A motorbike runs out of fuel => does it "break down"? (meaning: no more fuel so it stops while driving)

2. Waiting for a towing truck or a passer-by on car/bike to give some help => waiting to be "picked up"?

3. Does "stranded" is used only when you're stuck on a deserted island or can it be used when you're waiting in the middle of nowhere? If not, what is the right expression?

4. What is the message you get on your phone when your area is not covered by your mobile phone company? (meaning that you don't get any signal)

1) No it does not 'break down', that is when the engine ceases operating due to a mechanical problem. Instead it 'dies'. (Although breaking down could work...)

2) Picked up seems acceptable. I can't help but think a better set of words could be used but escapes me right now.

3) http://dictionary.reference.com/browse/stranded 4) No signal (I have a very simple phone)

1) Nope it would just be run out of fuel. You might say the "tanks dry" or "running on empty"

2) Waiting for assistance perhaps. You could say "flagging down passers by for help or assistance"

3) Yes, you can be stranded anywhere, even emotionally stranded or virtually stranded.

4) No reception perhaps. Or no signal.

1. If the vehicles runs out of fuel, you cannot say it broke down,

rather "it died when I ran out of gas" or " It ran dry"

2. Picked up does not give the whole sense of the situation but would be acceptable. Try " Waitng for the tow truck to give me a lift/ride".

3.Stranded is oft used as an exageration for when you are stuck somewhere that is deserted or desolate. Using it implies that you lack a mode of conveyace to become unstranded.

4. No signal.

According to what I have experienced some of native english speakers can't even tell a difference between your and you're.
I would suggest you to prefer person with good knowledge of english over native speakers.

Being the only one thus far to answer you from actual England (and therefore the God given right to use the Queen's English):-
All of your expressions will be acceptable.
(1) 'Break down' is a generic term from wheel falling off to running out of fuel.
(2) Waiting for a Tow Truck would be, 'collected' if you have called for it. Waiting for help could be, 'assistance'.
(3) 'Stranded' is fine if you are without transport in the middle of no-where.
(4) No signal/dead signal zone is fine.
Hope this helps (and yes, my first line is tongue-in-cheek)

Not a native speaker, but... What about "It ran out of fuel"? If you ran out of fuel, this is the perfect description of what happened ;) I've seen lots of movies where you could read "No signal" or "Lost signal" on the phone when... well... someone lost the signal ;)

Glad someone pointed that out, I was reading down the page thinking my bike doesn't run on Gas?

Also if you are learning english from a movie then don't forget the 'F' word.

F@%k, my f%@king car ran out of of f@%king gas.

or

I lost f %@king signal.

But all these depends on what kind of movie you watch. :P

"English Motherf*, do you speak it. "
Pulp Fiction

<English colony until 1901 excuse me. :P

God save the Queen.

And God save Malcolm Turnbull

And what happen at 2 minutes past 7 in the evening then?

Um, news at 7? Tea? I dunno. :P

Sorry, A very poor (English, therefore not very funny) joke.

'English colony until 1901 excuse me'

Yeah, I know... Bloody Pommie

Well, if I remember right, then the queer, uhm I mean: the queen, is still the queen of Australia, so your country is still a colony of England, right? :-)
Disclaimer: No insult intended.