Hello!
I bought an 03 Fatboy last August. Been a great runner. Currently 15,xxx miles.
A few weeks ago I started getting intermittent times where it would bog down. Both at a stop and while crusing. It eventually bounce back.
I thought plugs initially. Replaced those, ceramic had a couple bad spots. Plugs were a little dark, nothing super concerning.
Problem still happened. Replaced the fuel filter, pressure regulator, and fuel pump. Seemed to initially sound better and feel better.
Last week I had to limp home after about a 20 min drive. Bad bogging down. Replaced the crank sensor and the coil. The coil was slightly out of spec on an ohm test.
Filled up the tank and everything was running well. Drove about 30 miles and parked it.
This morning, issue happened a couple times on the way to work. I ordered the fuel check valve and hose. If there is a pinhole in the hose, it would explain everything.
Am I missing anything else? Homecoming weekend is fast approaching!

 

Just a suggestion, you may want to do an actual diagnosis of the problem rather than just throwing parts at it.

Throwing parts has three big negatives to it:

1) It can be really expensive, and you could waste a lot of money. Obviously on an older bike, replacing some parts isn't a bad thing, but it's better to zero in on the actual issue.

2) It's possible you may install a faulty part, or affect something else like an unrelated connector during the install. Now you would have two issues to deal with, and yet you don't know that you added an issue.

3) If you change more than one part at a time, you won't know what fixed it if you get lucky.

By doing a proper diagnosis, you will know what the issue(s) is before buying any parts. Once fixed you will know what was fixed, and learn about how your bike works. it is the cheapest, fastest, and most direct way to fix an issue...

Have you checked the engine management codes.....? If you have a code to start with, it may be a great shortcut to a good diagnosis of your issue.

If there are no codes, you need to find out for sure if the issue(s) is caused by fuel, spark, and/or compression. It's gotta be one or more of those three..

Unless I have some solid clues, I usually start with spark, then check fuel delivery, and if warranted, or no issues found in spark or fuel, check compression/leak down.

By your post, you obviously have an EFI bike. You would be amazed at the issues that can pop up from a bad, weak battery... or loose and/or dirty battery cables, especially the grounds to the frame (under the nose of the seat). Always start with the easy, cheap stuff first...

If you need suggestions on how to check for spark, fuel, or compression, or decide to do some testing before throwing parts at it, post your questions and/or observations and you will get plenty of help and suggestions...

Good luck with the repair and look forward to your additional checks and/or observations...

 

All excellent points as always from Mr. H.

One thing you did not mention is any mods on the bike. Also, does it happen to have a programmer in line?
By "Bog" what exactly is happening? Turning the throttle and no response, some power but way down, dies or tries to die?
When does it correct itself and start and run like normal - After it cools?

 

Check ohm reading on spark plug wires. Spray them with water in a very dark area to check insulation.

Check TPS for ohms. Key on and off with air filter off to make sure IAC pintol jumps in when off and back to last good idle position when you key on. It should respond quickly and loosely/rattley.

Clean area around butterfly with a rag wetted with carb or fuel injection cleaner. Do not spray it I. That will kill temperature sensor, IAC and TPS motor. It washes black crud in them.

Is there an aftermarket tuner involved?

Any codes stored?


​​​​​​PS..

Welcome Matt.

Hope you enjoy your ride here. Only as a suggestion, create a signature line for your bike, year, model, and all the code letters.

You can add that bike photo to the signature too.


Only as a suggestion, make your next new post over in the new member welcome area.

 

I run injector cleaner every 10th fill up.
I have an '04 EFI, amazingly reliable bikes.
Just sayin'.

 

My 04 has never had anything does to it except the brake light switches.


About ever 6 months to a year, I drain the fuel, add 4 gallons and drive it till it's warmed up.