almost 4 got , You probably should PULL all the plugs when finding your TDC as that being a high compression motor ! it will fight the process and be erratic in regards to the rotation if you leave any plugs in . If you get a chance send me a photo of the crank snout area (to the number I sent the photo's from) I may have a good solution for you . As DR. Johnny said there's got to be some remnant of tuning process somewhere on it .