When last working on the tear down of the 1981 GS650L engine I was in search of a 32mm socket to remove the clutch mounting nut. Now armed with a 32mm socket, the clutch plates removed, and my clutch basket holding tool, it was simple to remove the mounting nut.
You can then thread a couple of the 6mm bolts from the clutch springs into the primary driven gear spacer to pull that out and release the primary driven gear from the engine.
There are a few more bits and pieces behind the drive gear to remove so that the cases can be split including the oil pump drive gear and counter shaft bearing retainer.
Next it was on to the the stator side of the engine. Typical again to use a lot of Liquid Wrench and the impact driver to get the nine Philips head screws of the stator cover to free up from the engine case. Even with the screws removed, the stator cover was not budging. Ultimately, I used a large bolt through the starter gear hole to tap from the backside of the cover and break it free of the gasket.
Next was to get the rotor off of the crank shaft. It is a press fit on to the crankshaft which will allow replacing the seal behind it when the engine is rebuilt. At this point, both the clutch and the drive shaft were disconnected from the engine. If this was only a rotor issue, these would probably still be in place and you could have used the gears and jam the rear wheel to prevent the rotor from rotating while attempting to release the nut. The official Suzuki tools for this task add up to over $200. A bit excessive for the number of times I plan to remove a 1981 GS650 rotor. I found that a 22m crows foot and and a 17mm socket were all that I needed to remove the nut, but I was glad that the engine was still in the frame since I was able to anchor one wrench on the foot peg while putting a lot of force into the other wrench.
With the M12 mounting bolt removed, it is still necessary to pull the rotor off of the tapered crankshaft. Again, Suzuki had a special tool similar to a slide hammer that would thread into a larger diameter threaded hole of the rotor to hammer it off. I found instead that you could thread in a M14x1.5 pitch bolt (< $3 at the hardware store) into this hole that would bear against the end of the crankshaft and force the rotor off of the shaft. I thought it might be better to insert something into the crankshaft to prevent damaging the surface or threads. I had a clevis pin on hand that was the right dimension to fit to the bottom of the crankshaft. It worked, but it is still a lot of force and the clevis pin deformed some before the rotor popped off.
Everything that can be removed from the engine before removing it from the frame has been done. I have continued to work on loosening all of the remaining bolts throughout the engine before removing it from the frame. The frame has been a great work-stand and third pair of hands to this point.