...what is it for? I was trying to get as much of the old oil out of the engine as possible. I took it out and oil drained out, but not much. Fellow rider told me not to take it out after I already did it. Is it going to be okay?

 

You'll be fine. Put it back in. Do a search here on the forum and you'll see plenty of others that pulled that out also.

 

Here is the link, I asked about that same plug last week.

https://www.hdforums.com/forum/touri...rain-plug.html

 

No need to try and get all the oil out. Just drain, refill, and ride.

 

Check out photo "S". It is an oil pickup passage in the pan casting that directs the oil flow upward. It passes thru a secondary passageway in the transmission housing and from there the oil flow begins/repeats the oil flow circuit.

Many remove the plug and replace it with an oil temperature sensor unit. The plug is a tapered pipe thread, you can't screw it in too far before it becomes tight.

 

Either way the engine doesn't hold as much oil as the book says.That may be why the plugs are taken out uneccesarilly.What all do you drain to make it hold what the book says?
Big Block

 

The engine holds it, you are just not draining it. Next time, after you have drained the oil but before you remove the filter start the bike, give it a little throttle and watch another 10 - 16 ounces of old crappy oil spit out. Now when you add your four quarts of oil it will be right at the mid point of the two marks on the dip stick.

 

I removed the plug to install my oil temp. gauge sensor.

 

mctwist:

Not sure if this is the one your referring to, but there's a plug in line with/under the Cam Chest in the right Crankcase that's usually not removed unless your checking to see if the engine's "sumping" and retaining too much oil there.

 

Thanks guys. You were all referring to the correct plug. I really didnt mean to take it out, I just had a dumbass attack. I just let the oil finish draining and put a little locktite on it and put it back.