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'09 FLHP Losing Power

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Oscar

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09 Road King, 41000 miles. Starts strong, runs fine, but as I ride the motor feels as if its starving for fuel when I call for power. Especially at highway speeds, if I'm running 80 in 6th gear and slow down to 70, it feels as if I am lacking torque to get back to 80, however it can be felt on city streets as well. When I first start the bike and head out it is strong and seems to lose power gradually, like a loss of fuel pressure. My fuel economy has also dropped from about 34 to about 30 mpg since the problem got noticeable.

I bought the bike 4 months ago and have put 7000 miles on it, and the loss of power seems to be getting worse since I started riding it. It had been suggested by a mechanic when I bought the bike that there may be a pin hole and loss of fuel pressure in the lines in the tank. I opened the tank and removed the top plate, replaced the fuel filter and inspected the lines but saw no damage or places where lines would rub. I attempted to run the pump and check the lines for leaks but it appeared as if the regulator was spraying fuel and I couldn't make out any leaks.

It has electronic throttle, V&H Fuelpak, stage 1 air cleaner and true duals. It was throwing codes for running rich in both cylinders, I called V&H for lower values and since then it has thrown no codes.

I changed the plugs, and a Blackstone Labs oil analysis done last week shows no out of range metals, leading me to believe the rings are not blown, though I would probably need compression test to confirm that, and since I am not burning excessive oil or smoking I'm thinking I can rule that out, particularly with the relatively low miles on the motor.

If anybody's got any suggestions, I'm not sure what direction to go next to figure this out...
 
Does the fuel pump stop pumping after turning on the ignition and waiting a moment?
It should pump up the pressure and shut off. Is the bike back firing or sputtering at all?
 
Yes, the fuel pump does run and shut off after a moment, as normal. If I bump the starter, it again runs and shuts off as normal. It will occasionally have a sputter or two when started cold, more than my 08 FLHR ever did, but that is gone when warm. It will occasionally pop or backfire on deceleration but not often, I figured this on less than perfect tuning.
 
Have you checked for intake leaks around the manifold? Do you have a way to check the fuel rail pressure? If so, it may be worth while. If the regulator were bad, it could cause the same issue....
 
The decal popping is the symptom of a poor tune or an exhaust leak.

If the problem doesn't surface with a full tank of fuel and exhibits at some point as the fuel level drops, that would indicate a pin hole in the fuel line inside the tank. Typically a softail problem and more often than not a Deuce problem but it does occur in other models.

Have you checked the fuel vent system for a blockage? If the tank is not venting properly, a vacuum will build up in the tank making fuel delivery difficult.

I know absolutely nothing about the electronic throttle but would be looking there as well.
 
You say mpg down from 34 to 30. Neither are acceptable numbers from my exp. It was throwing codes for rich, but after adjusting per V&H no more codes. I'd remove the fuel pack and see what results are. You won't damage engine without the fuel pack.
 
Oscar said:
09 Road King, 41000 miles. Starts strong, runs fine, but as I ride the motor feels as if its starving for fuel when I call for power. Especially at highway speeds, if I'm running 80 in 6th gear and slow down to 70, it feels as if I am lacking torque to get back to 80, however it can be felt on city streets as well. When I first start the bike and head out it is strong and seems to lose power gradually, like a loss of fuel pressure. My fuel economy has also dropped from about 34 to about 30 mpg since the problem got noticeable.

I bought the bike 4 months ago and have put 7000 miles on it, and the loss of power seems to be getting worse since I started riding it. It had been suggested by a mechanic when I bought the bike that there may be a pin hole and loss of fuel pressure in the lines in the tank. I opened the tank and removed the top plate, replaced the fuel filter and inspected the lines but saw no damage or places where lines would rub. I attempted to run the pump and check the lines for leaks but it appeared as if the regulator was spraying fuel and I couldn't make out any leaks.

It has electronic throttle, V&H Fuelpak, stage 1 air cleaner and true duals. It was throwing codes for running rich in both cylinders, I called V&H for lower values and since then it has thrown no codes.

I changed the plugs, and a Blackstone Labs oil analysis done last week shows no out of range metals, leading me to believe the rings are not blown, though I would probably need compression test to confirm that, and since I am not burning excessive oil or smoking I'm thinking I can rule that out, particularly with the relatively low miles on the motor.

If anybody's got any suggestions, I'm not sure what direction to go next to figure this out...
Click to expand...

While I would agree that your bike does not have a large amount of miles it was a police bike and they do see a different service cycle than a civilian mount. The problem you describe could be the result of wear and when the motor is cold you have good compression and as it heats up and expands you are feeling the loss of compression and therefore power. A compression check and a leak down test will tell you if this is the problem. My other thought is that maybe the clutch is showing some wear and when cold it has adequate holding strength but as things heat up it begins to slip. You might try a clutch adjustment and see if this gives you back some power.
 
A compression and/or leak down test is never a bad idea but I just don't believe either will reveal a problem. Woudln't hurt and would establish the condition of the top end and possibly eliminate top end issues from the equation.

I missed the fuel economy comment of being "down from 34-30". I have a built all bore 107" carbed motor in my '02 FLHT. I ride the snot out of it and complain because I only get about 38mpg.

I think Breeze is onto something and removing the FuelPak might be revealing; the situation will change, or not, so at least you could rule the FuelPak out of the equation.
 
dolt said:
A compression and/or leak down test is never a bad idea but I just don't believe either will reveal a problem. Woudln't hurt and would establish the condition of the top end and possibly eliminate top end issues from the equation.

I missed the fuel economy comment of being "down from 34-30". I have a built all bore 107" carbed motor in my '02 FLHT. I ride the snot out of it and complain because I only get about 38mpg.

I think Breeze is onto something and removing the FuelPak might be revealing; the situation will change, or not, so at least you could rule the FuelPak out of the equation.
Click to expand...

This would be the easiest thing to check, run the snot out of it recheck your mileage and check for codes, IMO you are running pig rich your mileage should and could be better
 
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