2013 Ultra limited
S&S T124HC w/ 640 cams
58MM throttle body w/ 5.7 fueling injectors

The bike will start and idle just fine and accelerate on throttle less than 50%. If you twist the throttle past that without rolling it past 3,200rpm first, its stumbles, bucks and barely accelerates. If you're cruising at 3,200 RPM and go more than 50% throttle, it stumbles as well. I've checked, rechecked and checked again for an intake leak and haven't found one. Crank sensor has been swapped with a known good sensor as well as the coil. New plugs that came with the engine and gapped at 38 if memory serves me right. Fuel injectors are wired correctly. Fuel pressure upon priming is around 57/58 PSI. Bike was sent to a dyno with the assumption the tune was off. bike still doesn't work right. I'll be using an "inline" fuel pressure gauge to see if pressure drops off while riding but not currently aware if it is or isn't. If you roll the throttle it'll accelerate but a wide open hit it will stumble. It feels like a fuel issue but I'm not 100% sure.

 

Have you checked inside the tank , could be a plugged fuel filter , when was the last time it was changed out , how many miles ? Could also be a pin hole in the hose or a faulty pressure regulator .

Have you checked for errors ?

I believe the fuel pressure should be somewhere around 60-65 .

 

Did it run well after its initial tune when you added the S&S 124" engine?

If it ran well before, was this decrease in performance all of a sudden, or did it happen over time....?

Are you saying you took it to a dyno tuner and he sent back running like this, without so much as a guess to what is going on...????

If so, I hope he wasn't the guy who originally tuned it.... I also hope he didn't charge you..... probably time to find another tuner...

 

this is where I would start.

 

28k miles and I'd suspect its never been changed. From what I could find, the pressure regulator is set at 58 PSI and I'm right there at initial prime and it doesn't bleed off. I couldn't see any leaks but the way the regulator relieves pressure, its hard to see anything.

 

The issue started with the last engine but it started at the same time a knock started and I found a bad rod bearing so I assumed the terrible running was due to that.

Not only was I charged, the added $100 to put helicoils somewhere that I have yet to find as well as charge me for a license that I already had. While I agree, its time for a new dyno guy, this seems to be the general way they do things at every shop in my area. So, until I get it figured out, it is what it is.

 

definitely appears to be a fuel delivery issue

 

Started with the last engine and continues through this one? I’d go for pin hole in the tank hose, pump/regulator, filter, then external lines to the throttle body.

 

I'm having this exact same issue in my Springer, everything you've described. I bought a whole new fuel tank kit (fuel pump, regulator, filter, screen, and hoses) and I'll report how that goes this weekend. I have the parts but I tore my bagger down so I'll get to it tonight of tomorrow.

 

The 13 still has a system relay and associated wiring. You may have a bad relay or partially broke wire someplace. While you think it might throw a code. The bike may only look at system relay output at certain times and not while the bike is running. One thing you can do is start the bikes and start tugging the the wiring in different places. I'd do areas around the steering neck and the loom near the injectors. Try around the coil.

I would for sure got through the power and ground cables. The ground on the top of the tranny could be loose.. Generally it should throw a code..

If you suspect the charging system. You can disconnect the alternator and test ride.

You mention that you have an inline fuel pressure tester. What does it do when the issue occurs?? If you've only used to check pressure and not during test ride. It may be that the fittings on the bottom of the tank are worn..

57-58 psi is fine after the pump stops..