Well being the first time I've attempted to change the oil myself on my 2001 Fatboy 1450cc I mistook a plug directly underneath the engine cylinders and inline with the cam access cover as the oil drain plug. seems as if maybe a half quart of oil drained out and I realized my mistake and replaced the plug and located the correct plug on the frame. My long winded question is what was I draining ? it wasn't the trans fluid or primary, I know where those drains are. it looks like engine oil, is this a secondary oil plug for some reason ? your help would be much appreciated. ps. my manual doesn't show this.