When I bought my 85 ZN700 back in 2009 with only 1k miles on it, the idle mixture screws were set at 1 1/2 turns out. The caps had been removed so I don't know if this was the factory setting but since it runs fine and gets good gas mileage at that setting that is where I leave them. My bike gets 40mpg running around and 50mpg on the highway.
The way I used to set idle mix screws on auto carbs was to turn them in to lean the mix until the idle started slowing and then back them out just a little. It seems to be harder to get them just right using that technique on a bike especially on my V4s.
1985 Kawasaki ZN700 Shaft, 4cyl
1989 Yamaha Venture Royale
2007 Yamaha Royal Star Venture
Last edited by RoadRunner322; 03-27-2019 at 11:38 AM.