I put together a G3 recently which I ran yesterday for the first time. Nothing exotic, ceramic motor magnets, two-dot traction magnets, 7/23 gearing. Armature had a nice balance out of the box, comm has been trued. It's resistance is 6.3 ohms. The car runs very well for what it is, but the armature is getting extremely hot after several laps. I'm running 0.440" rears, and the car isn't rubbing on the rails. The gears, arms, etc. don't have any binding to speak of; everything seems nice and loose. I adjusted the timing bracket to back down the timing, with no effect. The 6.3 ohm arm resistance is a little higher than many of the arms in my other cars; could 0.2-0.3 ohms cause it to heat up this much? Any guesses concerning what is going on? I ran a G3-R on the same lane before and after, and it stayed very cool.

That small of a winding resistance would not account for a large temperature increase. I suspect something is still binding, and my most likely guess would be the bushings. You could try reaming the stock bushings to around 0.061 or install the newest Beedle bushings that have better fit and tolerances.

Other things to check...

Front end too low.
Motor magnets too weak.
Traction magnets dragging.
Body rubbing tire.
Tire rubbing chassis.
Gear rubbing chassis.
Gears too tight.
Brush tension too high.
Insufficient temperature assessment.

Knowing the exact temperature would help.

The car has stock G3 front wheels & tires. The traction magnets showed no signs on contacting the rails. I used an Indy body, so the tires shouldn't have been rubbing anything. I just about burned my finger when I picked the car up, which is about all I can say regarding temperature. I don't have an infared thermometer to get an exact figure, but you could smell the car getting hot. This same car ran OK before I changed the arm. I'll check the motor magnets out. Beedle bushings are illegal in the class I run with the car, so I'll look at reaming the stock one. The thing sure does run, I'll say that...I just don't know if it would finish a race.

High motor heat is usually an indication that the car is too low, try raising it up a bit in the front and/or rear....

I had the same problem not to long ago with a light bender I actually took skin off the end of my finger lol ( lets see a tjet do that!!!) I increased my tire dia. just a touch and it made all the diffrence. But remeber you are running a high rpm class and its going to get hot..but shouldn't get so hot that it stripes skin.. unless of course your trying to teach a corner marshall a lesson.. lol...


Dave

From the BSRT web-site:
The final size that works best for you is totally dependent on the height of the rails on the track you run on and well as your own personal preferences when setting up your race car. If you're not sure what diameter tire to use on a specific class of car we offer the following strictly as a recommended starting point:
Modified (ceramic motor & polymer traction magnets) .446 to .456
Polymer (polymer motor & traction magnets): .456 to .462
Also you may try reaming your bushings sometimes they are a little tight, even the pre-reamed ones.
mj

If you don't have a reamer,you can try pushing a Tyco axle through your bushings