Okay. So I'm on the side of the road letting the bike cool down so I can drive it home( why that works, I have no idea)

Drove for about 5 miles. Then it starts sputtering and popping at the carb and white smoke from the carb and then it dies.

I let it sit for 20 minutes and it cranks and drives for another mile and does the same thing.

What the H*** ?

So far I've deduced that it's either a carb that needs rejetting or extensively cleaned. Or the A/F valve needs adjusting because it's running too lean. But then why does it drive fine until it warms up?

The plugs and wires are brand new.

Thoughts? Oh and it's about to rain. So that's something.

 

You probably can't see it but there's white smoke billowing out of the carb

 

The first 2 things I would suspect are:
Fuel tank not venting - you can prove that by loosening the gas cap to see if that "fixes" it.
More likely, a failing coil or ignition module. Both tend to fail when they get hot.

 

+1 what he said up there

 

Here's a video... towards the end is full throttle. Then an exhaust backfire and the last pop is a carb backfire. It ran fine for 10 minutes until it got warm.

 

Tried the gas tank cap, didn't do anything different.

 

I sputtered my way home after having to stop 3 times and wait 20 minutes each stop...

ridiculous.

 

Do you have the Harley Service Manual? If not, it is highly recommended you get one.

Because of the rain and failure coinciding it may be electrical. Be sure to first check your battery terminals for corrosion or a loose fit. This has created some odd issues and is a common problem for cycles.

I'm going to guess it may be the crank sensor. This will effect timing. The tiny wires from the unit, in the nosecone, are close to the exhaust and often melt. Even the sensor itself melts. It can be Hot / Cold sensitive when failing. This is what sends the timing signal to the ignition module that triggers the coil. The white smoke could be unburned fuel from the misfire. Ignitions coil and Ignition modules can have loosened / corroded connections and are often intermittent, hot / cold sensitive when beginning to fail.

Also if the bike runs well at times then don't go throwing jets into the carb to see if it'll fix it. Obviously when the failing electronic / ignition component is NOT faulting the bike runs, so there is nothing wrong with the jetting of the carb!

The last thing it might be is the intake seals from the carb's intake to the heads. When these leak they draw air from the leak and runs really bad, including stalling and poor firing with the excess gas even spewing out of the carb. While it's idling spray the area between the intake manifold and the heads with choke cleaner. If it dies out it means there's a leak. Make sure you don't over-spray and damage paint, or over-spray and have it get sucked into the front of the carb. When cold you can have a good seal. Heat it up and the metals expand / contract and allow for a leak.

These are the simple things to check.

 

Awesome. That gives me some things to check.

I didn't think to put this but my key is super hot when I'm done riding. Not sure if that matters.

I do have the service manual, but when I posted this I was on the road.

 

Something definitely went squirrelly.

I ran a diagnostic test (held down the odometer while turning on the key.

Now the speedometer doesn't register speed and the odometer doesn't register miles. (I still have the back light)

And the turn signal doesn't turn off after a lean.

Everything kinda just failed all at once.

I rode the bike for an hour two weeks ago, no problem. Then last week I rode it to get a haircut (5 minute trip). Got me there fine, almost cut out on be on the way home.

I've been in troubleshooting mode ever since.