Here's the skinny...
I purchased the bike in April 2014 with 7664 miles. I currently (07/30/2017) have 46K miles. Yes...thats a lot of riding. She's a FLHRC (2011 Road King Classic EFI), and the original owner put on a stage-1 and Reinhart Slip-ons.

About 2-3 months ago, the bike was sputtering at higher RPMs (32-4000), under load (up gradual to moderate hills and headwinds), and whenever the bike was needing fuel (overtaking, passing...etc). Most recently, after initial startup, the bike dies.

Here is what I did to troubleshoot:
1.) I assumed it was the gas. I reside in the Denver. CO area where we only have 91-92 Octane fuel. I recall filling up (reluctantly) at a grocery store gas station. So, I allowed the bike to consume that fuel. I then filled up with SHELL Premium V-PowerPlus and added a bit of SeaFoam (SeaFoam Gas Treatment was suggested on another HD Forum thread). That didn't solve the problem.

2.) I checked the spark plugs. The front plug was caked with black carbon and the rear looked just fine. The plugs were last changed around 30K miles. I changed out the plugs. The sputtering continued.

3.) Fuel Filter. OH MY LORD! It was literally caked with black debris. It had never been changed since I had the bike. Note to self and all riders: CHANGE YOUR FUEL FILTER EVERY 25K MILES!!! I assumed that was the culprit. NOPE!! The riding was smooth and trouble free for about 60+ miles. Then, after parking the bike over night and taking it to work (mostly open highway...80+mph) the next day, sputter-sputter-cough-cough...under load, when it wanted gas, at higher RPM's and accelerating to pass/overtake.

That's where I am right now. I am fearful to ride it to work or anywhere until this issue is corrected. High Country HD off I-25 said they will run it on the dyno for free, but its NOT throwing ANY codes (no "check engine light").

I've read and researched and found out that the fuel lines in the tank may have a pin hole from chaffing and wear that takes place inside the tank.

That will be my next troubleshoot. But I would like to know if anybody else has had this similar issue and what did they find was the culprit? Could it be something more severe like a piston ring? Vacuum problem? Please help! I have MX (maintenance experience...mostly F-16's...not necessarily motorcycles...LOL)

Thanks, Brothers and Sisters

 

on a recent trip, i experienced a problem with a hestitation and lowered mpg.

it ended up be a vacuum leak on tbe tube on top of the throttle body

its called a fuel vent tube and it has a plastic cap on it that is prone to cracking and causing a vacuum leak.

suggest you start there as i would check easy stuff first

 

Thanks...Big! I will definately give that a look. You said its on top of the throttle body? I also check tech data (the manual) to see exactly what it is you are talking about...

Thanks for the reply

 

another freebie to check is the quick disconnect on the tank , i have seen a couple get partially plugged up or unseated enough to restrict the fuel flow

 

Wilco...Sidecar. All this advise is awesome! Thank you. Hopefully its as minor as that.

 

You did not say what tunner you have on it or if you have one.

 

I recently repaired a 2001 Fat Boy for a friend; that bike had about 33K miles and identical symptoms. It did in fact have two pinholes in the corrugated plastic line from the fuel pressure regulator to the tank outlet. The part is called "check valve" (the line and check valve are one piece and not sold separately). Cost about $55.

 

how does that front plug look now? how many miles on it?

 

Recent update 08/07/2017:
Yesterday evening (08/06), I took the air cleaner off the Road King and inspected all the electrical connections and lines. I used electrical contact cleaner on the main connector to the TPS which had some oil and debris inside the connector. I reassembled the air cleaner using the stage one air cleaner tech data (torques and other info). I started the bike, had it in neutral, knelt on the right side of the bike and actuated the throttle. The bike almost died several times and backfired a few.

Heres the kicker...since lighting in my garage was relatively low under the tank, I noticed a very slight "spark" under the head of the rear cylinder on one of the backfires. That CAN'T be normal...right? Could the sputtering and lack of power be caused of a break in the seal between the head and the top of the cylinder itself????

 

Rear plug wire grounding out is a common problem