Hi
​​​​​​I have an oil leak from this hose on my Fatboy 1340.

 

That’s the crankcase breather line that someone ran to the air cleaner. Not wise. I would remove it and just run the line to the bottom of the frame and leave it open. Don’t run too much oil in the tank.

 

Oil level is ok
massive oil leak in about 10 seconds

 

That’s called sumping. The bike probably sat for a while. That allows the oil from the tank to collect in the crankcase. When started, the only place it can go is out the breather. The fix is to run the engine to get the oil pumped back to the tank. Then run the engine more often. Do not add oil to the tank until the case oil is returned to the tank- it will only make it worse by adding more oil.

 

Put a longer hose on the fitting and route the hose overboard (not in front of the tire).

Before adding oil to the tank you should run the engine for a few minutes to make sure all the oil has been scavenged up from the crankcase.

Set the oil level about 1/2" to 1" below the filler neck, bike straight up.

Here is how I routed the crankcase breather and the transmission vent hoses on my `89 Softail:

 

I read on the forum that the little ball could get stuck.

 

How long was the bike inactive before you started it?

If the bike sits for an extended period make sure there is a drain pan below the breather hose.

If the bike pukes oil out every time it is started there is an issue.

Puking oil out the breather after being inactive is not uncommon, and does not indicate a problem.

 

2 months

 

That`s long enough...