What is causing my 3/4" Makita electric impact wrench to overheat and slow down

Question moved from Motorcycles category.
Full make and model helps in questions like this.

New 'bushes' or 'carbon brushes'. Are the bearings free? Is the fan spinning? It will overheat if it runs slow as the speed moves the air to keep it cool.

running hot
https://www.google.com/search?q=angle+grinder+runs+very+hot

running slow
https://www.google.com/search?q=angle+grinder+runs+very+slow

..

1) Unplug the electrical cord. 2) Loosen the bolt holding the motor to the frame. It should freely move up and down. 3) Remove the belt from the motor and wheel. 4) Replace the belt by placing it into the large wheel first then do the reverse. 5) Resecure the motor. Make sure the belt should be a little loose (tension). Too tight of a tension, would cause the motor to be slow and overheat.

The most likely things, in order, are:
1) There is too much dirt, dust or lint clogging the squirrel cage fan, slowing it down and causing the motor to overheat and shut off.
2) The motor is clogged with dust or dirt and is overheating and shutting off.
or 3) the ductwork is clogged, causing the motor to overheat and shut off.
God bless your efforts.

If I'm understanding u right, u overheat when the AC is not on?! If so, it sounds like the electrical fan for the AC is working & the electric, radiator cooling fan is not operating. This may be caused by a bad fan switch, coolant sensor fan relay, electrical short to the fan or it may be a simple fuse. Good Luck

there are countless reasons why a computer will slow down as it's being used several factors include age content your train of you how many programs you have running if it has viruses are dated cookie files history folders that haven't been cleared out all the way up through hardware failures such as failing thermal paste on the main processor causing it to overheat and slow itself down insufficient RAM for the programs are using how old is the computer and what is the operating system

One can expect a small amount of arcing from a carbon brush. If one brush is arcing more than another, or if the arcing is following around the diameter of the commutator toward the other brush, the brushes need to be replaced and commutator cleaned with a commutator stone.

Might be cooling fan clutch or the electric fan could be broken, the engine-cooling fan moves air through the radiator when your car is stationary or traveling at a slow speed, this air removes the heat from the coolant created by the engine, using the radiator as a conductor. When the cooling fan no longer works it causes the coolant to overheat which causes the engine to overheat. Also check the radiator, when the AC is turned on, the heat released from the condenser located in front of the radiator reduces the radiator's ability to remove the heat and the engine starts to overheat.

could be a bad temp sensor or faulty thermostat. so by cooling cycle do you mean electric fan, or water circulation. a bad thermostat will slow circulation down causing overheat even if cooling fans are on. a bad sensor will not operate electric fan properly or at all and car will get hot at idle or slow speed and cooler at higher speed. Keep in mind that electric fans can turn on at any given time so KEEP ALL FINGERS AND LOOSE CLOTHIG AWAY at all times.

A fan is on or off not slow do any fans in your house run slow because they are old?Your thermostat fan or temp sensor is bad

go to web site there is a parts list for your model and order the part