Runs fine down the highway, but

If I shut the bike off for a few minutes, it is hard to start back up. Then misses and pops until I get going again good. Once going down the road, It runs ok. Plugs are carboned up after only 25 miles. All 4 cylinders ran good before I tried to adjust the mixture screws. They were clearly backed out at very very different amounts. Tried 2 & 1/2 turns out and sooted up the plugs. Tried 1 & 1/2 turns out and same thing. I'm not sure which way to turn the screws to lean out the mixture. And does this affect only the low speed running? Or does this affect the entire rpm range. Floats were set a month ago and bike ran fine with tan plugs. I'm at a loss right now.

Just rode 52 miles and put 1.8 gallons in it. Lousy gas mileage for a 1982 xj650 Maxim. That works out to about 28.88 mpg.

 

Turns are only good as a starting point - after that you tune to the plug color and they can be all different. Big debate of effect but I believe everyone has agreed that even at higher speeds the throttle is barely cracked so there is an effect - the effect lessens as you open the throttle but of course you don't hold it that way for long.

In is leaner out is richer. If you are sooting plugs you are too rich and need to go leaner. Could be you have at least one air leak. 28 mpg is very low. I get low mileage on mine at 36 to 37 but I believe most of that is my size 2 or 3 mpg loss due to windshield too. The weight you carry will make a huge difference.