Motorization question

[dr_spock]

I used a piece of flex tubing instead of a technic axle for this build.

Camelback Steam Locomotive by dr_spock_888, on Flickr

It seems to run ok.  https://www.youtube.com/watch?v=FezhdIV6lzQ

 

[HenrikLego]

Hi again! I got the side rods to work as I wanted, and the motorization as well, kind of...
During the first event I was on this weekend the motors got really warm after an hour of operation and it actually stopped and wouldn't go anymore. After some time it started up again. When I got home I started to think about the gearing at the motors. I currently have this configuration (with more parts holding it together of course):

Thanks to Sariel's excellent Lego Gear Ratio Calculator it seems this produces the following output:
The theoretical output speed will be 346.7 RPM at 7V and 453.4 RPM at 9V.
The theoretical output torque will be 3.89 N.cm.

But is there anything that would prevent me from swapping the gears here? If I understand Sariel's calculator correctly this will give me the following output:
The theoretical output speed will be 124.8 RPM at 7V and 163.2 RPM at 9V.
The theoretical output torque will be 10.8 N.cm.

Could this cause less stress on my motors?
I understand the engine will go slower, but that's no problem.

Edited February 18, 2020 by HenrikLego