I don't have a lot of exp with the '80 sporty but check for a hose coming down from the oil tank and looks like it is clamped to the frame around where your frame and swingarm is. The hose would be coming from the lower backside of the oil tank. You want to drain the oil when its warm, get the bike running and let it warm up to running temp, the you can let it cool a bit, still warm but not too hot to handle.then take off drain hose and let it drain into a tub . Pretty sure it takes 3 quarts, so have a large enuf tub there. If you can't find it let me know I'll check for sure where it is tomorrow and let ya kno.

 

I think I found the hose...runs into the back of the engine case? just disconnect it there and drain? Manual says it is 4 quarts...the later Sportsters dropped to 3.

 

If the hose you are referring to comes from the bottom of the Oil Tank and attaches to a "dummy" pipe welded to a black bracket, then yes, that's it. I have an all original 89 Sporty and that's how the Oil Drain is set up. Just loosen the clamp, pull the hose off and let 'er drain.

 

You should move this question over to the pre-evo or sportster forum, might get more info for you make and model. Nice ride though I like those old iron heads.

 

Yeah thats probably it. Been a couple of years since I've seen an ironhead. There are 4 hoses all together. toward the front of the oil tank would be your feed and return line, then on the back the drain hose and up top would be a vent hose. The drain hose would have a clamp where it ends down by the casing.Prolly a gear clamp. disconnect there and drain oil. Don't forget to run the bike for a bit first ,to warm the oil and to pump any oil that may have seeped int the cases back to the tank.

 

Are you saying you have a stock configuration 1980 sporty? I mean, stock frame, oil tank, etc. If so, the oil drain is on the left side of the bike at the bottom of the oil tank, I beleive it's a 3/4" hex head plug. You don't need to remove any oil lines to drain the oil.

 

Nailed it...now I feel pretty dense ...I thought that was a trim panel like the right side...not the actual oil tank...big assed 3/4" bolt staring me right in the face...thanks eveyone for the help.