Harleys use what is called a dry sump system.That is why they have an oil tank in the first place.If you drain the sump you risk a dry start up.That is your choice.I prefer not to do that because I like my engine bearings lubricated.You are not leaving a quart in there more like a 1/4 to a 1/3.If you run it into the coke bottle you will not have oil pressure as long as you do it.Like I said it is your choice I prefer to have oil pressure on my bearings.I know the oil looks like crap.Changing ita couple times in a row would be much better in my opinion.

 

Looking in the service manual, the oil that rests in the case where the plug is is return oil, there is a nice diagrahm. since this is return oil going back to the tank, how would this mean dry start up?You would still fill the tank before starting the motor. The oil would flow down the hose into the pump, then when you started the motor the oil then gets pumped through the filter and through the rest of the motor. The only problem I see is the ouil would take longer to return to the tank.

 

Just a thought... Harley has been doing it this way for a long time... seems if that little bit of left over oil would have really hurt anything, they would have known it by now...

Charlie D.

 

The safest and best way to totally get all the dirty oil out of your bike is to do several oil changes in a row. Granted, this will be costly but, a lot less costly than the bill for a new engine or rod bearings. What oil that is left in the engine during anormal oil change is pretty much negligible. I would not run an engine when it was totally dry as one poster wrote. If youare this concerned about dirty oil in your vehicle, what measures do you take when changing the oil in your car? You are taking things to an extreme in this matter. The key is to do regular oil changes at regular intervals or, after going through harsh conditions to keep the oil fresh and clean. Ride safe.

 

Okay, you guys win, I called the stealer and they said not to mess with the plug, made some BS story about it having to do with the casting when the cases were made. Not due for an oil change for another 2000 miles anyway.

Im always trying to find a better way.

 

If there was a major advantage to removing all the oil from the engine, then it would be part of the oil change. There are several 100K+ mi. engines that never had the oil drained from the crankcase.

If you really want to remove that extra oil, then don't drain it that way. Do it the way I told you. Fill up the oil tank, disconnect the oil return line and put it in a pan, run the engine until you see clear oil, and top off the tank. Using that method the crankcase is never dry. By filling the oil tank with new oil you are still feeding oil to the engine as you would do so normally. The difference is that by disconnecting the return line the old oil is going into a pan instead of back into your oil tank. Then you just reconnect the line and top off the oil tank.

Personally, I think it's more trouble than it's worth, but that's your choice. Just make sure you actually disconnect the oil return line. There are three lines going to the oil tank: the feed line, the vent line, and the return line.

 

Just put your lips around a breather tube and blow (smokers just do the above posts)

 

Sounds like a glorious waste of time, honestly....

It's not gonna help OR hurt anything. Honestly.

 

Removing the oil from the sump could cause the oil pump to drain also and possibly lose it's prime.If it would lose it's prime you would find out what alot of work can be.I have sen oil pumps lose the prime on cars from draining the oil too long.When you lose the prime cranking the engine over will not get it back in most cases.The pump needs filled with oil from a pressurized oil filling system like in a lube shop or packed with petrolium grease.Without doing that the pump will not create enough suction to pull in oil.

 

If your that worried about it you should just cut the change interval in half, not a bad idea on an air cooled engine any way.