My eureka vaccuum model DS4065 will run fine without the end roller brush assembly installed. Once the end is put on the suction tube it runs for a couple secondes and then shuts off. Any suggestions?

There is a button on the handle that releases the suction tube from the floor brush housing. Once the suction tube is released from the brush assembly, you can install the attachments on the suction tube.

An Ultimate G has lots of suction. If you turn on your vacuum and the bag immediately inflates - that is how you can tell if your Kirby is moving air (suction). There is a more modern brush that came out with the Ultimate G Diamond and the Sentria that has stiffer bristles that dig up pet hair better.

Another way to test the suction is to spread some baking soda onto a hard floor and vacuum it up - you can see how much suction your Ultimate G has, or take off the vacuum head and put on a hose and test the suction at the end of the tube.

Ways to increase your Ultimate G cleaning efficiency. Take off the vacuum head and remove the brush roller. Attach your hose attachment and **** vacuum out the head. Put on a new belt, and remove any hair and or string or threads that may be wrapped around the brush roller. Put the roller back on and on the ends of your roller you will see that the ends spin and have numbers on them. If your vacuum brushroll is original - you could have your bristles rather worn and so you can align the #3 on BOTH sides of the brushroller. This would be a good time to consider upgrading to the Sentria Brush.
Remove the bag, and replace with the CLOTH Kirby bag. It has the best filtration and it has the best airflow (which increases what you are referring to as suction). If you want to go the cheap route - at least get the paper Micron Magic with HEPA filtration (but it has slightly less air flow)
Remove the side mini emptor from the vacuum and check to see if there is anything clogged up on either the vacuum or the mini-emptor.
If your engine is running and inflating the bag and you replace the belt, the brush roller and to the cloth dust bag - your vacuum should pretty much run like a brand new Sentria Vacuum. Your vacuum system is outstanding, but may benefit from a little TLC if you have been neglecting it.

Looking at the owner manual, there is no tensioner assembly.
If the motor is fixed in place and not loose, then you either have the wrong belt, or the brush roller is not properly installed, or the brush roller is worn out where the belt goes around the brush roller.

There is a blockage behind the brush between where the suction tube hooks up and the brush.

First, make sure you have the right belt, second, i am thinking that you are not lineing the roller up right, it will only fit one way. look at the ends of the roller and the grooves where it slides in, you should be able to see clearly how it goes.

You either have the wrong size belt, most likely too small, or you have installed a new belt incorrectly. When you open the cover on the bottom of your vac, you will see the pulley that moves as you flip the switch from floors to carpet. The belt does not go around this pulley. When activated(carpet) the pulley puts tension on the belt causing it to turn the roller. When switched back to hard floors, the belt looses tension allowing motor to cause suction but disabling roller. Also, the dial on top of vac is only to direct suction, not for disabling roller

no only take the bottom off ,there will be three screws,take the belt put in over the shaft of the motor , loop it ,run it over the silver spindle to the brush assembly ,replace the brush in the slot that it came from,the belt now is over the motor shaft running over the spindle ,and over the brush assembly,replace the three screws and you should be good to go.

That problem can be caused by the belt being stretched out and even though it is spinning when you look at it, with the resistance of the carpet it will stop.

With a model number I could tell you exactly how to change the belt, but most of the whirlwinds I've seen are similar.

You need to gain access the belt and roller. On most models there are two screws on the top of the nozzle inside one of the four indentions that run along each side. Once you take those out it allows you to take the hood off.

Remove the brush roller and old belt. Wrap the new belt around the motor shaft and place the roller through the belt loop and use the roller as leverage to stretch the roller back into the roller housing. It will take a little muscle. Give the roller a spin by hand before putting the hood back on. It should spin easily. If it doesn't then you might have pinched the belt and need to free it or the belt will just burn up when you turn the unit on.

A clog in the hose going down to the nozzle would also cause this problem, so check that hose when you take the hood off.

The brushroll may spin when looking at it but stops when pressure of the floor is applied. The belts stretch, so they look fine but are not. The smell - if it's a rubber smell - would also be the belt. Some, or most, brushrolls can get hair in the ends that could also cause a smell and belt problem.

if you have ran over any big objects you might try removing the cover from bottom take out the roller brush and see if it is clogged from the bottom