I had published this elsewhere, but thought you may also appreciate it.
Symptoms – running so roughly it could not be ridden and no error codes and only clue was the AFV was 147.

After checking all earths, voltages, plugs, HT leads, no air leak etc....

So what was wrong? – The internal “teabag” petrol filter was disintegrating but still passing fuel. The metal canister fuel filter was unblocked and still flowed OK. The pump ran OK – but noisy so suggesting internal wear and efficiency down. The hoses were all OK. The main issue was the O rings in the fuel regulator housing had broken up and so fuel pressure was being lost here and that with a tired out fuel pump dropped my fuel supply down to 11psi (max recorded) which was not enough to run the bike properly (needs c5-psi). The bikes computer detected the lean running via the O2 and whacked up the AFV to 147. With the new fuel pump AFV is now 102 and the bike is transformed.

So now all rebuilt. What have I learned/share. Buell XB’s have at least 3 different fuel pump assembly designs (I have bought a couple more as I was curious!) and they are all different.
To get the fuel pump assembly out of the frame (without factory tool) put a bolt into extraction hole with a large washer on it and lever across it to engine case and simple.
The pump assembly where it enters the frame has 4 bolts and had thread lock on and were stiff to get out so clean them up and re thread lock on assembly.

My bike is Nov 2002 XB9s and the fuel pump pushes directly into the regulator body. It uses 3 O rings to seal the join and these are no longer listed/available from Harley or anywhere. I have now sourced some and had to buy 100 – so if anyone needs some give me a shout. The regulator seals into the regulator housing with 2 O rings (large and small). They are a tight fit (need to be with 50psi of petrol) so easiest fitting is leave large O ring on reg body and remove small one and fit inside reg housing and use lube to make fitting it easier. The reg housing is plastic and after 17+ year living in petrol quite hard so hold it with something soft when you force the reg into the housing.

If you change the internal hoses as LunaticFringe says - use 5/16" fuel hose rated for submersion in fuel. Gates 27039 and ACDelco 32306 are 5/16" fuel hose that have the J30R10 specification.
The metal clips that hold the hoses on are not really designed for 2nd use, but I am sure we have all reused such in the past. I fitted new ones as they are pence/cents each and not worth the risk.

Change the large O rings that seal the assembly to the frame and use silicon grease to get it to slide in more easily.
The design of fuel pump assembly on my “03” XB is the longest of the types I have seen and so probably the trickiest to get in and out. You can do it with the swing arm in, but you have to use force and it will slide against the swing arm as you fight it in. Buell XB’s with tiny scratches here suggest a recent fuel pump swap!

On the outside of the fuel pump assembly is the external banjo coupling and this has 2 O rings of different sizes. They are available from HD. On my bike both O rings were brittle and fell apart. If they fail then you get petrol at 50psi onto your exhaust and rear tyre – so if your bike has not been touched – suggest you change these soon.
Fuel filter. The metal canister one. The forum lists alternative part numbers for these and I bought a few and the external dia. is too large to slide into the housing. I ended up getting them from my HD dealer and they are only £5 each so suggest you get yours from HD also.
Earth/Ground. The pump earths via a black wire with a cross head screw to the assembly body. Do this up very tight as if it comes loose then your pump will ultimately stop.
Wiring routing. The forum has tales of chaffed wires and each of my fuel pump assemblies has different wiring, wiring thicknesses and routing – probably depending upon who was on the assembly line that day.
Do all the pipe crimps away from the wiring and carefully position the wiring so it is not going to rub before refitting.
Corrosion. On all 3 pump assemblies I have (so I suspect all Buell XB’s) corrosion is starting on the external housing in bottom right corner. Clean this up and add corrosion inhibitor as otherwise corrosion has a habit of pushing metal faces apart and eventually a fuel leak.
So to rebuild your fuel pump assembly you will need:
1. Fuel pump: Probably various that will do –but a Quantum www.highflowfuel.com HFP 361 will do. They are on eBay, Amazon etc. Harley does a complete fuel pump assembly but it is £400.
2. Fuel filter metal canister: P0101.02A8 (£5) available from HD. The item is a Walbro 125-199 3291301
3. Fuel filter “teabag”: Came with the fuel pump
4. Fuel regulator which should come with 2 O rings: Unsure of the regulator part no as it came with the fuel pump but the regulator is marked as - 135-15 338 kPa 1533 IP
5. O rings Banjo: P0198.02A8 (2 O rings - £18!) available from HD
6. O rings Fuel pump out (depending upon type – maybe only on early c03 XB’s): Not available from HD – I have some if you need them.
7. O rings – where assembly seals to frame: P0121.02A8A
8. Low fuel level sensor: P0789.KA (£14) available from HD
9. Fuel pipe: 5/16" fuel hose rated for submersion in fuel. Gates 27039 and ACDelco 32306 are 5/16" fuel hose that have the J30R10 specification
10. Fuel pipe Clips
11. Silicon grease

Hope someone finds this of use.
Paul.

glad you sorted it

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Feros Ferio