Trying to figure out who ported the cylinder on my 1987 lt 250r motor I just picked up. It has SDF engraved on the side. Do any of you know who might have done the work based on this? Motor is supposed to be ported well and have a bunch of work done to it. The previous owner said it ran well and has low hours on a new sleeve with stock bore. He seemed like a very straight shooter when I talked with him. I have not pulled the top end off yet.
I am just curious if anyone has seen these initials before and knows anything about the quality of work?