I have a one horse power pump and i want it to reach 50 lbs of pressure\r\nand it wont go over 40 lbs.

This sounds like a plugged fuel filter or a failing fuel pump. If it has high miles a tune up including filter changes might be in order. If you have access to a pressure gauge the pressure spec. is 40-50 lbs.

Could it be a F-150 instead?
Ford Engine Bolt Torque Chart Bolt Torque Spec Chart for Ford Engines

These specs are for stock-type bolts with light engine oil applied to the threads and the underside of the bolt head. Moly and other lubes offer reduced friction and increased bolt tension, which will affect the torque figure. If you use after-market performance bolts like ARP's, you should follow the recommended torque specifications.

260, 289, 302 Torque Spec.
Fastener Type Torque Spec Main cap bolts 60-70 ft-lbs Outer main cap bolts 35-40 ft-lbs. Connecting rod bolts (40-45 ft-lbs. for 289 HP & Boss 302) Cylinder head bolts 65-72 ft-lbs. Rocker arms 17-23 ft-lbs. Intake manifold bolts 23-25 ft-lbs Oil pump bolt 23-28 ft-lbs. Cam bolts 40-45 ft-lbs. Cam thrust plate bolts 8-10 ft-lbs. Harmonic damper bolts 70-90 ft-lbs. Flywheel / flex-plate bolts 75-85 ft-lbs. Pressure plate bolts 35 ft-lbs. Front cover bolts 12-15 ft-lbs. 351W Torque Spec.
Fastener Type Torque Spec Main cap bolts 95-105 ft-lbs Connecting rod bolts 40-45 ft-lbs. Cylinder head bolts 90-100 ft-lbs. Rocker arms 17-23 ft-lbs. Intake manifold bolts 23-25 ft-lbs. Oil pump bolts 23-28 ft-lbs. Cam bolts 40-45 ft-lbs. Cam thrust plate bolts 8-10 ft-lbs. Harmonic damper bolt 70-90 ft-lbs. Flywheel / flex-plate bolts 75-85 ft-lbs. Pressure plate bolts 35 ft-lbs. Front cover bolts 12-15 ft-lbs. 351C, 351M Torque Spec.
Fastener Type Torque Spec Main cap bolts 95-105 ft-lbs. Connecting rod bolts 40-45 ft-lbs. (45-50 ft-lbs. For Boss 351C) Cylinder head bolts 105 ft-lbs. (125 ft-lbs. For Boss 351C) Rocker arms (non-adjustable) Rocker arms (non-adjustable) 5/16in. intake manifold bolts 21-25 ft-lbs. 3/8in. intake manifold bolts 28-23 ft-lbs Oil pump bolt 25 ft-lbs. Cam bolts 40-45 ft-lbs. Cam thrust plate bolts 9-12 ft-lbs. Harmonic damper bolt 70-90 ft-lbs. Flywheel / flex-plate bolts 75-85 ft-lbs. Pressure plate bolts 35 ft-lbs. Front cover bolts 12-18 ft-lbs. 360, 390, 406, 427, 428FE Torque Spec.
Fastener Type Torque Spec Main cap bolts 95-105 ft-lbs. Crossbolts for 406-427 40 ft-lbs. Connecting rod bolts 40-45 ft-lbs. (53-58 ft-lbs. For 406 and 427) Cylinder head bolts 80-90 ft-lbs. (100-110 ft-lbs. For 1963-67 427) Rocker arm shaft bolts 40-45 ft-lbs. Intake manifold bolts 32-35 ft-lbs. Oil pump bolt 12-15 ft-lbs. Cam bolts 40-45 ft-lbs. Harmonic damper bolt 70-90 ft-lbs. Flywheel / flex-plate bolts 75-85 ft-lbs. Pressure plate bolts 35 ft-lbs. Front cover bolts 12-15 ft-lbs. 429-460 Torque Spec.
Fastener Type Torque Spec Main cap bolts 95-105 ft-lbs Connecting rod bolts 40-45 ft-lbs. Cylinder head bolts 140 ft-lbs. Rocker arms (non-adjustable) 18-22 ft-lbs. Intake manifold bolts 25-30 ft-lbs. Oil pump bolt 25 ft-lbs. Cam bolts 40-45 ft-lbs. Harmonic damper bolt 70-90 ft-lbs. Flywheel / flex-plate bolts 75-85 ft-lbs. Pressure plate bolts 35 ft-lbs. Front cover bolts 12-18 ft-lbs.

Ford Engine Bolt Torque Chart Bolt Torque Spec Chart for Ford Engines

These specs are for stock-type bolts with light engine oil applied to the threads and the underside of the bolt head. Moly and other lubes offer reduced friction and increased bolt tension, which will affect the torque figure. If you use after-market performance bolts like ARP's, you should follow the recommended torque specifications.

260, 289, 302 Torque Spec.
Fastener Type Torque Spec Main cap bolts 60-70 ft-lbs Outer main cap bolts 35-40 ft-lbs. Connecting rod bolts (40-45 ft-lbs. for 289 HP & Boss 302) Cylinder head bolts 65-72 ft-lbs. Rocker arms 17-23 ft-lbs. Intake manifold bolts 23-25 ft-lbs Oil pump bolt 23-28 ft-lbs. Cam bolts 40-45 ft-lbs. Cam thrust plate bolts 8-10 ft-lbs. Harmonic damper bolts 70-90 ft-lbs. Flywheel / flex-plate bolts 75-85 ft-lbs. Pressure plate bolts 35 ft-lbs. Front cover bolts 12-15 ft-lbs. 351W Torque Spec.
Fastener Type Torque Spec Main cap bolts 95-105 ft-lbs Connecting rod bolts 40-45 ft-lbs. Cylinder head bolts 90-100 ft-lbs. Rocker arms 17-23 ft-lbs. Intake manifold bolts 23-25 ft-lbs. Oil pump bolts 23-28 ft-lbs. Cam bolts 40-45 ft-lbs. Cam thrust plate bolts 8-10 ft-lbs. Harmonic damper bolt 70-90 ft-lbs. Flywheel / flex-plate bolts 75-85 ft-lbs. Pressure plate bolts 35 ft-lbs. Front cover bolts 12-15 ft-lbs. 351C, 351M Torque Spec.
Fastener Type Torque Spec Main cap bolts 95-105 ft-lbs. Connecting rod bolts 40-45 ft-lbs. (45-50 ft-lbs. For Boss 351C) Cylinder head bolts 105 ft-lbs. (125 ft-lbs. For Boss 351C) Rocker arms (non-adjustable) Rocker arms (non-adjustable) 5/16in. intake manifold bolts 21-25 ft-lbs. 3/8in. intake manifold bolts 28-23 ft-lbs Oil pump bolt 25 ft-lbs. Cam bolts 40-45 ft-lbs. Cam thrust plate bolts 9-12 ft-lbs. Harmonic damper bolt 70-90 ft-lbs. Flywheel / flex-plate bolts 75-85 ft-lbs. Pressure plate bolts 35 ft-lbs. Front cover bolts 12-18 ft-lbs. 360, 390, 406, 427, 428FE Torque Spec.
Fastener Type Torque Spec Main cap bolts 95-105 ft-lbs. Crossbolts for 406-427 40 ft-lbs. Connecting rod bolts 40-45 ft-lbs. (53-58 ft-lbs. For 406 and 427) Cylinder head bolts 80-90 ft-lbs. (100-110 ft-lbs. For 1963-67 427) Rocker arm shaft bolts 40-45 ft-lbs. Intake manifold bolts 32-35 ft-lbs. Oil pump bolt 12-15 ft-lbs. Cam bolts 40-45 ft-lbs. Harmonic damper bolt 70-90 ft-lbs. Flywheel / flex-plate bolts 75-85 ft-lbs. Pressure plate bolts 35 ft-lbs. Front cover bolts 12-15 ft-lbs. 429-460 Torque Spec.
Fastener Type Torque Spec Main cap bolts 95-105 ft-lbs Connecting rod bolts 40-45 ft-lbs. Cylinder head bolts 140 ft-lbs. Rocker arms (non-adjustable) 18-22 ft-lbs. Intake manifold bolts 25-30 ft-lbs. Oil pump bolt 25 ft-lbs. Cam bolts 40-45 ft-lbs. Harmonic damper bolt 70-90 ft-lbs. Flywheel / flex-plate bolts 75-85 ft-lbs. Pressure plate bolts 35 ft-lbs. Front cover bolts 12-18 ft-lbs.

I do not know but you could call a Harley Service department or better go there in person and ask.

Recommended Suspension Air Pressure: FLHX, FLTRX, FLHR/C

Solo rider up to 150 LB up to 68KG10-20 0 psi0kPa
Solo rider up to 150-200 LBup to 68-91 KG0-10 psi0-69kPa
Solo rider up to 200-250LBup to 91-113KG10-20 psi69-138kPa
Solo rider up to 250-300LBup to 113-136 KG20-30 psi138-206kPa
Solo rider up to over 300LBup toover 136KG30-50 psi206-345kPa

Solo rider with capacity luggage of 40 lbs (18 kg) up to 150LB up to 68KG 10-20 psi 69-138kPa

Solo rider with capacity luggage of 40 lbs (18 kg) up to 150-200 LB up to 68-91 KG 20-30 psi 138-206kPa
Solo rider with capacity luggage of 40 lbs (18 kg) up to 200-250 LB up to 91-113KG 30-40 psi 206-276kPa
Solo rider with capacity luggage of 40 lbs (18 kg) up to 250-300LB up to 113-136 40-50 psi 276-345 kPa
Solo rider with capacity luggage of 40 lbs (18 kg) up to over 300LB up to over 136KG 50 psi 345 kPa

Rider plus passenger ALLWeights 40-50psi 276-345 kPa

Maximum GVWR ALL Weights 50psi 345 kPa

If Tour-Pak is installed, add 5-10 psi (34-69 kPa) to shock pressure.

Do not exceed 50 psi (345 kPa) suspension pressure.

Sounds like fuel pressure is too low-either a weak , old pump, or you need to change the fuel filter-most likely, the pump, though. Check the fuel pressure specification for your car, most mpfi systems require 40-50 lbs. of pressure.

If in the past your system can build-up pressure up to 40 psi even if the supply valve is open and water is being used in your house, then your pump impeller maybe already worn out that's why its pumping capacity was reduced.

Unlikely although a surge tank is a very good idea. Our well pump here at the ranch is a 2 horse power and we have 75 lbs of pressure

I would check the holding tank pressure, if you have one with a bladder. Turn electric off to the pump, and drain all water from the tank. Take a tire pressure gauge and check the tank pressure at the air valve on top of the tank. That pressure should be two lbs less than your cut-on pressure. If the cut-on pressure is 20 lbs, then the tank pressure should be at 18 lbs. If there's too much pressure in the tank, it wont let the pressure switch work correctly. If you get water from that air valve, then the bladder is ruptured, and a new tank is needed.
I hope this works for you!