One day soon I'm sure there will be a service manual, but there is a huge cost with producing this. And unlike a ninja 250 which can go unchanged for 20 years (1988 to 2007) or Chilton or Haynes manuals for cars that sell hundreds of thousands of units, for someone to take the time to write a service manual there needs to be some incentive in it. It's not Zero's job to make the manual. It's the aftermarket like Haynes or Chilton, but the quantities need to rise first.
This is why we have the forums. To help each other with simple things that can be done at home. I'll bet within 5 years, someone will buy a Zero, dissect it, take pictures, and write a service manual and then sell it to Zero owners. The number of Zero's on the road need to go up just a little more for that financial return of selling manuals to make sense. Maybe a manual for like $500 if they sold 100. But they would have to be preordered and presold I think for someone to be willing to do this, because someone would probably scan it and post it online and so that would prevent future sales and make it not worth an experts time. Or it would have to be cheap enough that everyone would buy it and not want to get it for free to make it worthwhile for someone to take the time to do this.
How many people would be willing to pay $500 for a service manual? If 100 people on here want one, I have a friend who could probably do this. He has been so busy being hired for design work, he was going to try to work less, so he raised his rates a little to $250 per hour and what happened? He got more work lol. But he would be the right guy to do it. Some of you might know who I'm talking about. He lives for physics with everything he does, lets put it that way.
Maybe someone on here with some free time could try to make one, and make it open source and then all of us could pitch in to make it better over time. I think for now that would have the highest chance of success towards eventually getting a manual.