Good balance job Fairmontweve!  Sounds like it's turning 6 to 7 hundred RPM in the video, I wouldn't run it any faster until you can verify speed.  Also sounds like a lot of misfiring!  If you slow it down by about half you should hear a definite rhythm, fire,fire, then coasting churning noises, fire, fire, coasting churning, fire, fire, coasting churning,  etc.  A load on the engine is a must!        Leland

I would add weight to balance the flywheels if it was mine.  To balance my 6-1 I made weights out of channel steel that straddled the ridge between the spokes.  Held in place with set screws and spray foam to try to avoid causing stress points.          Leland

I've never seen the generator pulley in person to see if there is enough metal to cut the belt grooves deeper to speed up the generator but in photos it looks like that would work?  You would have to add field resistance to keep the voltage down and you could get a transformer for 120V applications.  A Start-O-Matic would be way cool to have  !                              Leland

Something I thought was cool when I noticed it is that every starter with an integrated solenoid that I've had apart, the pull winding goes to ground through the motor windings so that the armature rotates as the pinion gear is slid into the ring gear.  This makes for easy gear meshing.  I think you would want to see some rotation as the pinion gear is sliding  .  I fixed a starter problem where the pull winding was open but it had a hold winding that could just barely slide the pinion out and sometimes it would work right, and the next try sounded terrible before it would crank.      Love these icons  !                                  Leland

When I first saw my Metro jumping off the ground, this image of the heavy piston and rod staying at TDC while the rotation of the crank jerked the rest of the machine up towards someplace where the inertia forces averaged out.  The next image in my head was of a saddle and me riding the machine around the yard!  That seemed like it would put too much forces on the flywheels and crank and cause failures that could be painfull so I started thinking of how to tame the engine.  I thought the cast in weights were too light and tried adding more to them but it turned out that more weight was needed about 90 degrees ahead of the cast in weights.    I guess that inertia causes a time lag?  Anyway, the weights I added are well on their way down when the crankshaft throw jerks down on the piston and rod.  It was very helpful to have a dial indicator showing me the amount of back and forth while could see and feel the up and down movement.  Taking out the COV plug and spinning the Metro with an electric motor also made it easier to see what different amounts and positions of weights did.  I also tried adding weights to one side or the other and that didn't make any difference so I'm guessing that my flywheels are both about the same.  My engine now runs smooth enough although I can feel the thump of the power stroke several feet away.  I plan someday to expand the frame of the genset so I can fill it with concrete and set it on a rubber mat.  I put a real heavy pulley on the generator to try and get rid of the flicker and that made the belt chirp on the power stroke and didn't completely eliminate the Lister flicker problem.  Then I machined the rear brake drums off a one ton van to take tapered bushings that allowed me to mount them to the 6-1 crank.  Bingo, no more flicker!  Someday I may test the flywheels off the engine to see how close they match, I'm sure my engine would bobble around a bit if it was on a trolley.  The next thing I want to do to it though is rig up an electric starter and maybe a glow plug; my spine is too messed up to allow me to spin the set by hand and I doubt I could get it started on a cold day.                       Leland

Maybe it did seize but un-seized itself as soon as the heat input stopped?  I'd keep an eye on the oil in the crankcase in case the rubber O-ring seals melted or hardened up and allow water into the sump.  I always thought these engines might take something like this OK because of the cast iron piston and thick castings in general.  I hope your luck holds up!                      Leland

Hi selmawp, welcome to our group!  I think shipchiefs' idea is the best solution and it should work just fine.  A little tricky to do but easier than anything else.  Yeah that's a lot of wobble and I'd expect you would have seen some run-out when the engine was running.  If you ever need to get machine work on that flywheel for a starter gear or something you get it bored for a taper bushing then.  I hope it runs true after you shim it.  If I made that flywheel I'd have been very careful to bore the center hole to the exact size and then mounted it on a spud that ran true, then turned the sides and flat O.D. of the rim.  I hope it runs true after you shim it because it may have been a  lose fit on what it was mounted on to turn the rim.  I don't know if a little run out would hurt anything at the speeds these things run as long as you put a spring tensioner on any belt if you run one from the flat of the rim.