I'll do my best to keep this as brief as possible. I put a Sputhe rear stabilizer on my bike, and this issue started literally the next day. Maybe a weird coincidence.

The bike is an 01 FXDX with stock carb, jetted and tuned (S&S stage one filter), 95" kit and Reaper 525 cams.

Sometimes while riding, usually when gunning it from 4th to 5th, or even wide open 5th, the bike will stagger and lag for a second, then seemingly hook up and take off. For instance, if I'm going 70mph and flick the wrist, it will seemingly delay, my speed will drop to 60mph, then suddenly
Im going 80mph. Also, I get a pretty wild popping on decel, not just a single "pop" here and there, but a wild "crack crack crack crack" like a Fireworks Finale is going off.

Every so often it will just die at a light also. I'll have power, but it would be as if I closed the choke too quickly and the engine bogs down. Electrical power is stil there.

The MOST annoying thing is that it's very intermittent. Sometimes it's all ****ing day from the second I pull out of my driveway, sometimes nothing happens for a week or more.

Early ideas on another thread is that there was a pinched wire in the Sputhe, but there is not.

The OTHER issue which might be part of the same, is that my clutch lever keeps coming loose within a couple days. I tighten it at the cable to where it feels comfortable, and in a few days it's floppy and won't shift. Could the clutch be fried? Am I like gassing it and not moving so the engine is getting flood with fuel that isn't burning off or something?

Any ideas would be helpful, thanks.

 

You remove / loosen the exhaust during this install - if so check for leaks

From there - it could be a dozen things and needs to be gone through systematically..., eliminating things it ain't

Do a complete clutch adjust (clutch first..., then the clutch cable)

Ghost

 

Adjusted the clutch inside the derby cover, still popping.

Any other ideas?

 

My first thought is something might be clogging, or pinching in the fuel system. But, I don't know enough about the older bikes to really say anything of real value. I had an issue like this on my old buick, and it cleared up when I swapped the fuel filter.


Now you've got me researching carbed TC fuel systems.


Good luck

 

Still running the stock petcock?

 

I am.

 

First step is verify you have NO intake or exhaust leaks.
Once that's ruled out,

I have zero experience with a stock carb, but the high speed lag sounds like a lean stumble, possibly caused by accellerator pump circuit (or equivalent, if stock isn't equipped).

The decel pop could be a mixture problem at idle. My Mikuni only takes 1/8 turn in the mixture screw to make or break a decel pop.

Frankly, I'd dump that stocker and get a Mikuni 42 or 45 and have it tuned.

 

I also have a 2001 FXD and I have experienced this problem, once with the carb and more recently, with an old battery. I have also had a loose pipe but I did not experience anything with the way the engine was running, but I could hear that something was not right with the exhaust.

It may be time to rebuild your carb...a leaky vacuum piston diaphragm, or just gunked up and sticking, a worn accelerator pump diaphragm, or a miss-adjusted float could cause this.

Also, make sure you have a good battery/charging system...I have had some weird problems with an old battery getting near its useful service life. Check the cables and charging system...it is an easy quick check and worth the effort anytime anything weird starts happening.

 

You might want to replace the stock petcock with a non-vacuum one. Also check your tank vent.

 

I've been considering it, but most people say there isn't a huge benefit. An experienced tuner should be able to work the same magic with a stocke CV carb. But others say the seat of the pants response with a Mikuni is way better.

I'll consider some new carb or carb rebuild options.