i just bought a 1980 flh shovelhead a week ago. the seller told me that he had just changed the oil. before i drove the bike away, i checked and the oil looked good and full. over the last few days i have put maybe 200 miles or so on a few short rides. checked the oil last night and tank is empty!!!! when I pulled the bike in the garage after my last ride, it ran and sounded fine. i have not seen a trace of oil leaking in the garage or on my driveway from riding in and out. where that much oil went that fast, idont know. where do i go from here, is there a chance there is no damage? do i just fill the oil back up and go? prime oil pump?

 

Sounds like it sumped.

This is from another thread in here...it will explain.
http://www.bigboyzheadporting.com/showthread.php?t=87

 

Check valve in the oil pump is likely bad, oil is in your crankcase and will return to tank when motor is started. Or seal is bad, and oil is now in your primary. Not sure how to check your primary level, but would do that first. If oil is not there, start motor and look in oil tank while motor is running while watching psi gauge to verify oil is returning.

 

that makes sense. so in that case, i likely avoided any damage?

 

Doubtful if you damaged anything. You do need to fix the check valve though. Unless you don't mind oil blowing out the air filter every time you start it.

 

thanks for the good news, i almost **** myself when i saw an empty oil tank.

 

Agreed, nothing damaged, but on a Shovelhead, the breather hose does not go to the air filter, it will go directly onto the ground.

Remove the check ball from the oil pump, if it looks good reinstall it, hopefully the problem is just a bit of debris on the check ball seat.

Put a pan under the breather hose when you start it up.

All the oil is down in the crankcase, it will be scavenged back to the tank when the engine starts, but some will blow out the breather hose, don`t panic when you see it...

 

How can i confirm this. Would it be safe to put a half qrt or so in the tank and see if it drains down into the case

 

No, you don`t need any more oil down in the crankcase, first get that check ball apart and make sure that everything looks good, look for any debris that might be in there. Once it is back together, fire it up so the pump can scavenge the oil out of the crankcase.

 

+1 I would probably just replace the ball and spring since they are not too expensive. While in there clean the surface that the check ball sits against to remove any dirt or abrasion.