I have a 2000Harley dyna fxdx 1 time it shut off on freeway like some one turned the key off? ond speedometor sometimes does not work right...please help!

SOURCE: Will the wheels from a 2000 Harley-Davidson FXDX

Check to see if they both have the same diameter axle. Harley went from a 7/8 inch diameter axle to a 1 inch diameter axle sometime around that time period.

SOURCE: changed primary cover on 2000 dyna super glide

You'll have to take the cover back off and look very carefully at the inside in the starter area to see where it is hitting when it engages, and then use a grinder to relieve the area in the primary cover where it's hitting. Several test fits and removals may be necessary seeing as it is not OE.
It's probably just hitting enough to stop engagement of the teeth, or bind the starter. Other wise it would not work at all. Check to make sure primary is tighten in sequence properly. Take your time, relax, have a beer and look at the job as a learning experience.

SOURCE: i have a 2003 dyna glide fxdx changed the stator

Did you change the rotor as well? I've seen several new rotors from Harley that weren't magnetized correctly. Check it using a screwdriver. It should almost take the screwdriver out of your hand, Compare it with your old one.

To test the alternator output, unplug the regulater at the engine case. Look down into the connector at the engine case and you'll see two metal connecors in the plug. Using a digital volt ohm meter, put he meter in AC voltage, 50 volts or greater range. Make sure you meter is in the AC voltage scale or it won't work. Now, start the engine and bring it to high idle. Put one of the meter leads on each of the metal connectors making sure that you don't touch the engine cases with the leads. You should read 32-40 volts. If not, your stator is not generating current.

If you read at least 30 volts here, I'd suspect the regulator is bad.

Good Luck
Steve