I have an 06 Night Train. It is carbed.

I had it dyno tuned at Harley for a few mods I did and it has been running excellent for the last two years.

I recently lowered the rear end about 1.5 inches and had 10" t-bars installed. Right after this is when a few issues started. When my tank is full it runs fine at all speeds. Now all of a sudden if I am down to about a quarter of a tank and on the highway I start getting a lot hesitation when I hit the throttle. I used to get around 150 miles to a tank. Now when I hit 100 miles the bike starts to feel like its running out of gas when I should clearly be able to get more mileage out of it. It really starts bogging down bad. Keep in mind that my gas gauge still says I have a quarter of a tank left. Doesn't make sense to me, it happens mainly on the highway. If I'm just cruising around town at lower speeds it doesnt do it at all, once I stop and fill her up the highway problems go away. This really has me confused

I tried running a pint of seafoam the other day thinking it might clean out the carb but that didn't do the trick.

Any help would be appreciated, thanks in advance guys.

 

Nobody?

 

Its the pin hole in the gas line. getting more common all the time.
Most start doing it after 5-6yrs.. Mine done it at 33k and 5yrs last summer.. It ain't the miles its the yrs

Most Thinks its the Ethanol eating the fuel hose..

Just need to relpace all hose's inside Ur tank and a new fuel filter while Ur in there.

heres a vid on changing filter and lines..



Or take to Ur shop..
Mine started it 500 miles from home, we went to three dealers in WV to find one who had all the parts.

2 1/2hr later and $330.00 lighter,, I was back on the road...




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He says his bike is carburated. Isn't that a fuel injection problem?

 

According to that video you are correct. First thing he mentioned is for a fuel injected bike.

 

At 60 psi, fuel injected bikes can have problems with only a small hole in the fuel supply. With a carburated gravity system, I wouldn't think it would matter.

Train, I don't know your bike, but the first thing I'd look at is whether there's a fuel filter somewhere in the system which might need to be replaced. The second thing I'd look at is whether there might be something like loose paint clogging a petcock, or some other orifice in the system. The recent "fuel cap recall", as far as I can tell, has to do with paint coming off the filler neck. Mine is blistered and peeling.

 

What about the angle of the tank? The OP mentioned he lowered the back about 1.5" and the bike runs good on a full tank. I'm thinking the angle of the tank is causing the fuel to run past the petcock after 100 miles or so. Just a thought.

 

Petcock issue from my experience. Run it dry suck out the last drips of gas,nrestart the bike til it fails. I thn would put some rags strategically around the area and remove the the petcock. I would also see about getting a small led tipped flashlight than can articulate and peer into the tank. Does your tank have a reserve setting? If so, how is this running? When you've sufficiently cleaned the tank then refill, reset trip to zero and see what happens. Trial and error with gas sometimes.

 

I never trust a harley gas gauge... lol What happens when you flip it to reserve??? I'm thinking the gauge is off and sounds like you're running out of gas?

 

As mention by another.
Bike was lowered at REAR so angle of tank is altered.
Pick-up tube for fuel might be starved for fuel because of slight rear end drop.
If rider is a bit heavy and has passenger on back that could also alter fuel level at pick-up tube even more.
Quick Highway acceleration would cause fuel in tank to move to rear of tank and starve bike of fuel and a continued request for fuel would cause hesitation and then when you slow down fuel sloshes forward and all is good again until cycle repeats.
Possible Solution: A cheap solution would be to raise back end of tank if possible..Some older bikes had just one bolt while others had two bolts..Maybe a thick rubber washer to raise back end of tank 0.5 inches...alternatively the correct process but more expensive is to lower the front suspension also.