Ok, i seem to be having a problem with my mini Titan.
After about 4 minutes of flight my ESC tries to cut off because it gets very hot. The motor is also very hot. This does not used to happen earlier. I noticed that without the canopy I still get the usual 9 miunutes of time and the motor?ESC is not that hot.

I checked for the usual culprits :
- Opened all openings in the canopy
- Checked belt tension
- Checked pinion-main gear mesh
- I am still hovering at mid point, which translates to 65 on throttle. Checked the curve - is linear and i rarely go over 70 on the throttle
- blades are tracking

Any ideas ? The same setup worked fine a few weeks back. Is it that the summer has set in ? and temperatures have gone up by say 10 degrees ?

Make sure your ESC is mounted properly, with both sides getting enough airflow over it. Usually only the heat-sink is exposed. 

I had similar issues once, and here is my thread about it on our other forum :

http://rcqatar.com/helicopters/scorpion-commander-45a-esc-heat-problem-solved/

well i m not a senior member of this forum,but i guess this is not the correct place to post your problem,

this is sales division .... of rcindia

My ESC is the Ace Hobbies one and is covered in heat shrink tubing. Would it be a good idea to open it ?

Moved

Wow. Not sure how i missed that. I think i had 2 windows open, one on the Sale thread and the other on Helis. Looks like I posted on Sale board by mistake. Thanks Anwar for correcting this, and Pankaj for spotting it right away !

quick response ,anwar sir

That would be an extreme step (and not recommended), as it may affect the physical integrity of the package. The shrink tube helps hold the heat sink properly pressed on to the chips. Just ensure good airflow, even if you have to expand the holes a bit.

You can also try going higher on the throttle curve, as it could also be a matter of load on the motor with not enough RPM to sustain your hovering pitch.  Curves are a bit tricky, it is easy to go over or under, and both are problematic.

Well,
The ESC is on its back and the holes in the base plate just under it. I tried to mount it vertically, on its side today, i think that might increase some airflow, as when it was on its back, the openings were getting closed .

Even then i had the ESC get hot and cut off after 4 minutes.

Without the canopy, i still get a full 9 minutes with no over heating.

Then, i removed the training gear, and wow , i got 9 minutes with the canopy, and though the ESC did not cut off, the motor was hot to touch.

I think i should now progress to flying without the training gear. The heli felt wonderful. light and much more responsive. HOWEVER I need to get used to how it looks. Should i practise looking at the gear ? or the blade-plate the rotor makes ?

That would mean your training gears are too heavy. 

Motors do get warm to moderately hot in many cases. But this cut off still shows you are borderline in terms of power system (or the setup of your power system via correct throttle curve).

Since the motor overheating problem was not going away, I finally decided to replace the stock motor with a Turnigy 2215H motor.
Was able to install this motor without any problem at all ! All screws/sizes everything fits in perfect.
Worked like a charm, and after a 5 minute flight, barely warm ! I mean it ! It was like not even warm at all !
ESC is also not as hot.

To anyone who is flying a MT with the stock motor, i suggest going this route and replacing the motor. Turnigy 2215 looks very nice.