The 87´ ls650 takes 2.5 quarts. DO NOT PUT IN THREE!!!! You will start to have lots of back pressure and gas will come out of ur overflow when ever u stop. The oil filters are hard to find but go to an bike shop. The oil filters on the 87´ are on the right side next to the footpeg and exhaust. Its three allen bolts. The drain plug is on the left side bottom. Barely enough room to get at but i had to use just a 17mm wrench to get at it. Just make sure to NOT USE 3 quarts.