I was stuck. I'd removed just about everything on my engine with the intention of splitting the crankcase, but I couldn't turn the nut on the flywheel magneto. I tried holding it with a large strap wrench and using a socket wrench—initially pushing counter-clockwise and then, in exasperation, trying the other direction in case I was dealing with a reverse thread—but I simply couldn't get any movement. I'd leave the engine on my workbench for a couple of days, and then go back to it, repeating my futile efforts to remove the nut holding the flywheel. Nothing. It wouldn't budge.

Meanwhile, I was also struggling with my clutch. I tried building a contraption to hold part of it while I turned the 46mm nut holding everything in place, but as with the flywheel I simply couldn't get it apart.

Finally, I did something sensible and took both parts to a local motorcycle shop, where one of the mechanics put an air impact wrench on the flywheel and removed the nut in an instant. Turns out it has the standard "left loosey" thread, in case you find yourself in a similar situation. The same fellow quickly identified the kind of flywheel puller to use—an important bit of information that Yamaha neglected to include in its service manual for the CV80. A minute later, he'd popped the flywheel off the crankcase. For those who are still curious, you can order a standard Yamaha 27mm x 1.0 left-hand thread flywheel puller (similar to the one shown above) for a few dollars. It's the right tool for the job.

I had less success with the stupid clutch. According to the service manual, several tools are used to hold and disassemble this vital part, but Yamaha no longer has the tools and it's not clear what else you might use. After conferring with the mechanic, I decided I will probably end up doing what others have done: I'll find a volunteer with strong arms to hold the clutch firmly while I wrestle a spanner on the nut. That might be easier said than done. So far I haven't been able to find the right wrench. I've seen pictures of what I need: Beedspeed, a scooter shop in the UK, advertises a 46mm clutch nut spanner for £5.99 plus shipping costs. I'll probably order one.

"Always use the right tool for the job," I keep telling myself.