Turkish carry-on weight
 

My personal opinion is that if your carry-on is so heavy that you need help to get in into the overhead bin... then you're carrying on too much. And some airlines have strict policies about staff not helping passengers lift things...

But you shouldn't run into a problem in J with ground staff weighing your carry-on. You might have problems at TSA though, as I struggle to imagine a standard roll-aboard weighing that much unless it's full of books, metal bars or over-sized liquids...

I don't know about IAH, but I've flown TK from MIA twice in J. In MIA you could NOT use mobile Boarding pass, and they did NOT have TK staff, but contractors at the checkin desk.
I has unlucky and got a grumpy Agent who didn't even know the rules: "Sir, you can't take two bags with you"
"Oh, pardon me, I think with Turkish Airlines, Business Class passengers may take two cabin bags. It's so confusing these days with different rules for different carriers… Let's see, right here on the Reservation it says 2x cabin bag…" (said this in a really polite way, but she had been grumpy and unfriendly from the start...)
"OH, you are in fact right, sir. BUT I HAVE TO CHECK THE WEIGHT" - one of my carry ons was actually 11 kg (instead of the 8 kg allowed) and that was one of the only two times in C and another two times in Y where they took it from my - I did several hundred flights with this bag, usually at 10-12kg, 95% of those flights on European/asian carriers that only allow 7 or 8 kg. 99,5% of the time they did not weight it, and not once did anybody check the dimensions ( 1,5 cm / half an Inch too much in each Dimension for LH/TK/LX/SQ/AB).

Next time form MIA I had a very friendly Agent as usuall, and of course she never even asked for me to put anything on the scale.

I never, ever encountered any Problem at TSA or other security checks anywhere. I can lift that bag with one arm, get it in the overhead in a breeze, it fits perfectly, and in most planes the overhead bins is labeled inside with something like "load limit 46 kg" for one compartment that takes two of thoose bags.

in short: TK will rarely weight cabin bags (in C). IMHO the highest risk for this happening is US airports. If it happens, it happens at checkin. Watch the agents while you stand in line, If one seems unfriendly to other passengers or always puts all their cabin bags on a scale, Chose to write that important emails on your Smartphone when it's your turn and the unfriendly one would be the one handling you.... let somebody else pass in front of you and wait till one of the friendly ones is available.

Continuing on with the topic, I remember reading somewhere on TK website that Elite/Elite Plus can also take two carry on's even when traveling in Economy. Is this correct?

That's a tricky one - data Points:
Bought economy ticket with my profile (elite+, I am also the passenger). Reservation says "1 carry on"
Upgraded with e+ voucher, Reservation still says "1 carry on" although it's now in J
somewhere on their Website it also says "1 carry on for economy" and additional piece for elites that sounds like "+20 kg or +1 checked in piece". I searched this repeatedly during the last years and could never find their Website stating the 2 carry ons for elites

But:
Sign at checkin in CGN says: Y 1 carry on. elite, elite+ and Business Class: 2 carry on. I took a photo 4 weeks ago but can't post it right now. Official TK sign (not handwritten)
and: whenever I travel in any class with TK, I always take 2 carry ons.
I've been elite+ for several years now, but if my Memory is correct, it also worked when I was LH FTL travelling TK on cheap eco sale (long time ago).

IMHO it depends much more on how your carry on looks (my two pieces are the maximum dimensions, but look small next to me - different story if my wife would take the same two bags).
I rarely use the checkin counters any more because everything fits my two cary ons for almost every trip and TK offers mobile check in from most airports - but those signs should help if you ever have that "2 pieces for elite" discussion.

Have you seen those signs at others TK counters, too?

Thought the 1 carryon +1 'personal item' maximum was FAA requirement regardless of class

I haven't seen the signs but I always thought the 2 carryon + personal item was for j and e+. I fly with a similar setup, a spinner plus 40L backpack. No one's ever made any fuss about backpack. Though, they love to weigh the spinner at the counter.

https://cimg5.ibsrv.net/gimg/www.fly...80bc2bc2a1.jpg
cabin baggage rules, TK checkin at CGN, Sept 2018

There is also no "only one piece to US" rule from major *A carriers - I have taken multiple flights to/from US from DUS/FRA/MUC/ZRH/IST on TK/LH/LX/SQ during the last years and never ever did two pieces + personal item cause any problems anywhere (except for the one grumpy checkin agent at MIA mentioned above).

If I remember correctly there once was a "only one piece allowed at LHR" rules some years ago in LHR that was enforced by airport staff, regardless of airline or class flown, but it was abondoned again a few years ago. Maybe you've read about that somewhere (might have been incorrectly qouted if someone connected at LHR to get to the US)

Kudos to you for getting the spinner compliant!