I used this stuff
and I used 2 cans of it after changing it after about 1-2k intervals. First can was AWSOME! Last can I believe plugged the holes really good to a point that it felt very clogged. When I flushed that stuff and put in 10W30 oil (GTX from Wal-Mark for $8, 4L jug!!!!) it runs very smooth now.
My recommendation is don't put it in the winter! It will do no good it needs heat to stick to the cylinder walls, and start ups will be hard in winter. Also flush it out after a few 2-3K KM. But overall I think this stuff works.