Sporster oil pump prime

You have to prime the oil pump if not that the cam is not driving it witch 2 things can happen cam gear stripped or rod is broken most likely just needs to prime

Oil suction filter may be clogged. Did you check it?

remove the pump and the cover off the gears
fill the spaces of the gear teeth with Vaseline or clean grease
this is priming the pump so that a vacuum is created to suck up the oil
new pumps will not be primed
the grease /Vaseline will dissolve in the oil and will not cause any problems

You don't give the year and model, and I'm sure its not a Cutlass Ciera if it has a 231.
Usually its a good idea to pack the gears with grease or vaseline to help prime the pump. Since the pump is mounted on the outside of the engine it can be very difficult to get oil from the sump into the pump gears for the first time.

From the diagram in the service manual, it looks like the front of the crankshaft has two keys, in line with each other. Those two keys drive the crankshaft timing gear, the oil pump drive gear, the oil thrower (all inside the timing cover) and the crankshaft pulley (external). If your oil filter is dry, you're not pumping any oil. Pull the timing cover back off and see if the oil pump drive gear is correctly locked onto the key in the crankshaft.

oil pump is driven by the camshaft gear by an oil pump drive shaft located under the throttle body/intake plenum. the oil pump is located inside the oil pan/engine block.

Oil Pump REMOVAL & INSTALLATION 22R and 22R-E Engines

1. Raise and support the vehicle.
2. Drain the oil from the engine. Fig. 1: Exploded view of the oil pump components on 22R and 22R-E engines
   
   
3. Remove the oil pan.
4. Remove the four bolts holding the oil strainer.
5. Remove the drive belts.
6. Remove the crankshaft pulley.
7. If equipped with air conditioning, remove the compressor and its bracket. Support the compressor out of the way with the hoses attached. Do not discharge the system or loosen the compressor lines. Fig. 2: Bolt location identification
   
   
8. Loosen the oil pump relief valve bolt.
9. Remove the five retaining bolts and remove the oil pump assembly with the O-ring.
10. Remove the oil pump drive spline from the crankshaft. To install: NOTE: Pack petroleum jelly between the oil pump gears. This will prime the pump during initial startup.
    
11. Slide the pump drive spline onto the crankshaft. Place a new O-ring in the groove.
12. Clean the threads of the upper retaining bolt of all grease, oil or debris. Clean all the bolts holes.
13. Apply sealant to the first 2 or 3 threads of the upper bolt. Install all the bolts. Tighten each to the correct tightness. Bolt (a): 18 ft. lbs. (25 Nm); bolts (b) 14 ft. lbs. (19 Nm) and bolts (c) 9 ft. lbs. (13 Nm).
14. Install and tighten the relief valve plug to 27 ft. lbs. (37 Nm).
15. Installation of the remaining components is in the reverse order of the removal procedure.

3VZ-E Engine

1. Raise and support the vehicle.
2. Remove the engine under cover.
3. Remove the front differential.
4. Drain the oil.
5. Remove the timing belt.
6. Remove the crankshaft timing pulley.
7. Raise the engine slightly and remove the oil pan.
8. Remove the two bolts and nuts; remove the oil strainer and gasket.
9. Insert a drift between the cylinder block and the oil pan baffle plate, cut off the sealer and remove the baffle plate. NOTE: When removing the baffle plate with the drift, do not damage the baffle plate flange.
   
10. Remove the seven bolts, then the oil pump and O-ring. If the pump is difficult to remove, use a small plastic mallet to carefully tap the body of the oil pump. To install: NOTE: Pack petroleum jelly between the oil pump gears. This will prime the pump during initial startup.
    
11. Apply sealer to the oil pump mating surface, running the bead on the inside of the bolt holes. Position a new O-ring in the groove in the cylinder block and install the pump so that the spline teeth of the drive gear engage the large teeth on the crankshaft. Tighten the mounting bolts to 14 ft. lbs. (20 Nm). Fig. 3: Do not apply too much sealant on the pump surface, it can block the oil passage
    Fig. 4: Align the pump drive and the pump
    
    
12. Installation of the remaining components is in the reverse order of the removal procedure. Tighten the oil strainer bolts to 61 inch lbs. (7 Nm).

Best way to draw a prime is to put a long screwdriver blade (no handle) attached to an electric drill down into the oil pump drive slot (distributor removed). I actually use a distributor that has the top cut off without the cam gear, and just attach the drill to the shaft, but the screwdriver works pretty well too.
Only other option is to pack the inside of the pump with light grease, but that would require pan removal and I doubt you want to do that!!
Many pumps are replaced because of low pressure but the cause is generally a bad bearing...If that's the case you may find it difficult to prime.

If you're having that much valve noise, you have probably lost oil pressure for some reason. Take your oil filter off the engine and take the spark plugs out. Spin the engine with the starter and watch for oil to pump out of the fitting for the oil filter.

Now, you didn't mention how loud the valve noise was. If you have indeed lost oil pressure to your tappets, the noise will be quite noticable, not just a slight rattling. Your bike will sound like a pea thrasher.

The late model Sportster oil pumps are not like the older models that were so bad about shearing the drive pins. The late model doesn't have the pins. They have flat drive angles on the oil pump shaft. About the only thing that I can think of that would cause a loss of oil pressure on a Sporty is a piece of trash got into the tank and is blocking the inlet to the pump or the pump is air locked for some reason. Unscrew the oil pressure sending unit and spin the engine over long enough to pump out a few ounces of oil.

I've only seen one Evo Sporty lose oil pressure. Someone had tried to stop an oil leak in the oil tank by Creme coating the tank. Creme is designed for a fuel tank, not an oil tank. The coating cannot take the heat of the hot oil, becomes brittle and starts flaking off.

Good Luck
Steve

If the filter is intact, then the dirt was in the line to begin with. Disconnect the inlet line at the pump and blow out the line with compressed air (from the tank side). You might clean the oil tank while you are at it. The blow-out is unnecessary if replacing the above parts. Put some oil into the new pump to prime it. Don't try to fix the damaged plastic gear.