I was on a 140 mile run today and half way through I found the bike hesitating. Idling low, lots of popping on decel and heavy flat spot under full throttle acceleration. Made it home ok.
Bike starts and idles so I we have spark. My symptoms are classic lean conditions and fuel starvation, so I figure low fuel pressure. I don't have the H-D fuel pressure adapter so I used my MAC fuel pressure gauge.

I removed the quick disconnect at the tank, then slide the spring clamp that holds the fuel line to the quick disconnect and removed the fitting, installed my T-fitting between the quick disconnect and the fuel line, slide the spring clamp back and secured the T-fitting to the quick disconnect fitting and re-installed the fitting, connected my guage to the fitting. Turn on ignition switch to run and a whopping 30 psi and then bleeds down immediately, did this a couple times and purged the line of air. Started bike and fuel pressure reads 30 psi and after idling dropped to 28 psi. Spec is 55-62 psi = Not Good! Actually, I tested it several times and then it took a big fat crap, O fuel pressure and I can hear quite a bit of by passing in the tank so maybe I have the split pressure hose in the tank or a faulty regulator??? Guess I am lucky I made it home.

Here are some pics of how I hooked up my guage














Note; you could just run a plastic tee fitting with just a small amount of fuel hose, I just used what I had in front of me.

 

do you hear gas squirting around in the tank when you turn the run switch on?
most of the time it's a pastic line inside the tank, it rubs a hole in itself.

 

Thanks, thats what I thought it would be. However, I found the large U-clip that holds the fuel fuel filter in the housing was not snapped in all the way and it was blowing off fuel pressure before the filter, WTF? It must have never been fully snapped in because there is a tang that retains it and it worked its way out, every time it primes its self the housing kind of expands and then contracts when you shut it down. I was able to snap it back in and now have 58psi.
CB

 

Nice troubleshooting pics. Glad you solved your fuel pressure dilema.