Curious to what fluid this screw plugs . I know it's obviously not a drain plug

 

Its a service only plug in the bottom of the crankcase,,actually in the cam galley. Even though a Harley is considered a dry sump motor, the level of the return side of the scavenge side of the oil pump is apx 1 1/2" off the bottom leaving about 12-20 oz of oil that is spun by the crank. This lubricates the inner cam bearings. Somewhere there must be an exact amount so if there is a sign of oil sumping in the motor a mechanic can check the amount left at a level shut down. Your actual engine oil tank is the pan on the bottom of the transmission and of course a plug that has a passage way up thru that tank to the transmission. Oil drains are actually hex bolts along with the allen wrench hole in them.

 

The oil pump. Leave it alone.

 

Do not loosen that one

 

Yeah located the three 5/8 drain bolts with Allen holes in them . Just also noticed a few other plug style screw ins and was wondering what they went to .

 

Thats like saying dont push that button. So what happens if somebody takes it out. Whats it do to the motor.

 

Haha exactly . I'm guessing since it's motor oil if you drained it it would just fill back up when the engine is running but it would be dry for a few seconds before the oil got back to it .

 

Not so much what it does to the motor, but more what it can do to the case. Many have ended up with a cracked case when they tried to remove that plug. I don't know what they use for thread locker when it's put together at the factory, but it sure stands up to it's name.

 

its a tapered pipe plug. there is a ton of stress put on the case when you are putting that plug back in if you tighten it too far.

i believe that the scavenger oil change system uses it also.

 

So that's not the same bolt in our cam galley on our Softails? Only thing in my 2008 service manual is to use loctite sealer on the pipe plug. Not long ago, some one indeed tightened the NPT tapered pipe plug in and cracked a big hunk out of the side of the block