How hot motors are supposed to get?

I jus read that you'd burn them up fast if you overvolted or they were hot... how true is this?

I know efficiency of the motor drops when heat kicks in, but then again, my Razor overvolted scooter (24V motor @ 60V+ on a full charge), and my Razor chopper (36V @ 55V+ fully charged). The scooter is touchable after lots of abuse, but HOT.

The chopper... eh... it's... frying-pan hot. I can guarantee you can't hold your finger on it for 3 seconds - even the shaft is hot (I found out the hard way)...

So... eh... how long would I get (as in life) with this

not to much longer if it really is frying pan hot.... it also depends on the run times
you never really want to overvolt a motor more then 12v......... noramally a a extra 12v wont harm the motor at all.......... 24v is pushing it.........

but anymore then 24v you shouldnt be riding it know more then 20mins at a time
if the motor gets too hot... the windings will turn into mesh on the inside and will be tost
also you should put a fuse or breaker on the + motor wire
a 40amp fuse would do
hoped this help

40 amp? That's it

I have those cheap controllers (they whine slightly) - I read they just dump amps into the motor... so it wouldn't blow the fuse right then?

Mmm... there's a burning smell from the motor now that I noticed...

well if it keeps poping the fuse you can always go higher.....
buring smell isnt a good sign

Yes it isn't.

I don't get it thuogh, this 750W motor is buring up from 24V worth of overvolt.

I have a Razor scooter (friction drive), running 30V overvolt (24V motor, running 4x 12V and 1x 6V)...

And it works fine! Doesn't get as hot as the chopper... is it because it's geared low?

oh yea! srry i forgot to mentiond that... yea gearing does make a difference
a 3 to 1 gear ratio would be harder on the motor then a 6 to 1 gear ratio cuz it takes less time and less efort for the motor to get the bike going with a higher gear ratio
then with a low gear ratio accelration will be slow and most likey a lil harder on the motor so it takes more stress when you constanly slow down and accl
hope this help