I am trying to remove a Centurion B849 from the impeller. I removed the 4 bolts. I come to find out that the shaft is threaded; so in order to rotate the motor, how do I remove the electrical wires on the other end?

Soak the shaft and impeller splices with diesel fuel or store bought nut/bolt loosening spray and tap often over 24 hour period while it soaks and permeates the contact area. Tap impeller with a wooden mallet to remove,

Separate the plumbing portion of the pump from the seal plate which is attached to the motor. The bolts will be a 9/16 inch hex head, that are visible facing the motor. Remove those bolts. That will then allow you to pull the motor and the seal plate away from the plumbing portion of the pump. Remove the diffuser which is covering the impeller, and then the impeller will need to be unthreaded off of the motors shaft. The motors shaft, will need to be locked. You can do this by removing the Cap on the backside of the motor and you can use whatever tool required to keep the shaft from spinning. Once you are able to lock the shaft, you can read the impeller... Note* some styles will have a screw in the middle of the impeller securing it to the motors shaft? This screw is Backwards thread, not normal thread. If your pump has this screw, need to remove it first, then you will be able to unthread the impeller off of the motors shaft.
once the impeller is removed, you can then remove the two halves of the shaft seal. Very carefully reinsert the new shaft seal into the proper places, just the way they were prior to you removing them.

Reassemble in backwards order as you disassembled everything.
good luck

J5s is a back pull out. Remove the bolts holding the front casing to the motor. Remove the diffuser. The impeller will either be screwed on. ie the impeller is moulded with a thread, or key wayed .ie a separate metal nut holds down the Noryl impeller and a small piece of "key" steel keeps the impeller on the shaft.
Remove the rear fan cover, and either use a flat screw driver (if there is a slot in the rear of the shaft) or a shifter (if the shaft has a hex) or you may have to prise the fan off. to get a good hold of the shaft.
Hold the rear of the shaft, and with the correct socket undo the hex on the impeller. either the nut or the whole impeller will come off. If just the nut type. Use cable ties to thread down the centre of the impeller to the out side and join. do this in a couple of places.Use these as a lever point to pull off the impeller.
The seal just pulls off. there is two parts stationary and rotating.( 18th may, yourve probably worked it out by now)

The correct way to remove the impeller is as follows:
First, drain gas, remove spark plug wire, remove back half of impeller cover, wear safety glasses and gloves. Take your time and be careful!
1. Remove bolt holding impeller in place.
2. Apply penetrating lubricant, such as PB Blaster to the end of the shaft.
3. Insert a 1" to 2" stud into the hole in the end of the shaft. This stud does NOT screw into the hole and should fit easily into the hole and drop to the bottom. This acts as a spacer for the next step.
4. Screw a 7/17 x 20 - 1 or 1.5" hex head bolt into the hole in the end of the shaft. You will probably encounter resistance as the shaft has seen some wear and tear. Screw the bolt in until it bottoms out on the stud installed in step 3. NOTE THIS IS A FINE THREAD BOLT NOT A COARSE THREAD. YOU WILL HAVE TO LOOK AROUND TO FIND IT. I FOUND MINE AT ACE HARDWARE IN THE AISLE OF 10,000 BOLTS, AFTER I WAS TOLD THERE WAS NO SUCH THING. AGAIN: 7/16" X 20 TPI aka 7/16" FINE THREAD OR FT.
5. Get a 1/2" air impact wrench or a big 1/2" breaker bar with a pipe extension. You are going to need some torque! An electric drill probably won't work.
6. Place either a wooden block or attach a pair of vise grips to the impeller to prevent it from rotating.
7.Drive the 7/16 x 20 bolt into the hold using highest torque device you have. Continue to hammer it with the impact wrench. After 10 - 20 seconds it will "pop" loose.
8 I have seen two schools of thought for replacement. One school says to slather some grease or non-stick on the shaft before reassembly. the other says to leave it dry to provide for a closer tolerance fit. I've done both and seen no difference.

The shaft seal more likely than not needs to be replaced. If your shaft seal has been leaking for any length of time, the bearings could be damaged and this should be replaced. The whisperflow uses a PS1000 shaft seal and is fairly easy to replace (most seals available online or at most swimming pool retail stores). It is best advised not to run the pump until you have had this inspected by a licensed pool technician or have changed out the seal.

1) Make sure breaker/power to pump is off. 2) Remove the six bolts holding the wet end to the seal plate. 3) Remove the diffuser to expose the impeller. 4) Remove the screw in the middle of the impeller by turning clockwise (left hand threads). 5) Remove the dust cap at the rear of the motor and use a wrench to hold the shaft while you remove the impeller by turning counterclockwise. 6) Once the impeller is off, remove the four bolts holding the seal plate to the motor. 7) Press the old seal out of the seal plate and clean it thoroughly. Remove the ceramic part of the seal from the impeller and clean it thoroughly as well. 8) Apply a thin coat of lube (I prefer Magic Lube or Lube Tube) to the seal plate and impeller where the new seal will go. 9) Remove the new PS1000 shaft seal from the box (being careful *NOT* to touch the ceramic or carbon face with your fingers), press the metal part into the seal plate carefully, try not to bend the metal and make sure its completely seated against the seal plate. 10) You can now install the seal plate back onto the motor and secure with four bolts. Press the ceramic part into the impeller, use cardboard or paper between your fingers and the ceramic face. 11) Once you have seated the seal into the impeller, hold the motor shaft and thread the impeller on until snug, then reinstall the stainless screw, remember it is left hand thread so you'll have to turn it counterclockwise. 12) Reinstall the diffuser over the impeller and then install the wet end onto the seal plate using the six bolts, don't overtighten them.
Check the pump for operation and you should be good to go!

To get to the Impeller you need to remove a series of bolts, or a large clamp, that holds the two halves of the pump together. Once you do that, if their is a diffuser (housing that goes over the impeller), remove it. To remove the impeller, you need to lock the motor shaft. You can do this a couple different ways depending on the motor. There will either be a small cap that grants access to the motor shaft on the back of the motor, or you remove a larger housing that grants access to the wiring and other components in the back of the motor. If it's the small cap, then you can hold the shaft with a wrench. If it's the larger housing, then you can slip a wrench (probably 7/16") under the thermal overload switch and onto the shaft to lock it in place. Now you can unscrew the impeller. Check to see if the impeller has a screw in the center. If so remove this first. It will be reverse thread. The impeller should spin off counter clockwise. If the impeller is very tight, be careful not to damage it. If you don't have an impeller wrench, I strap wrench, or very large locking pliers with a rag around the impeller works well. Hope this helps. If you need further assistance post a reply in the comments, and don't hesitate to leave a good thumb rating if you found this helpful. Thanks, and good Luck!

Might be a screw in middle of impeller with reverse thread. If so, remove. Remove back cover of motor, hold center shaft with wrench and unscrew impeller from shaft.

Most likey righty loosey lefty tighty.

this usually indicates an air leak in the plumbing. it will **** air because it is easier than water if there is a leak in the plumbing.
good luck David