Sorry I read the first part of the story wrong. Different problem altogether. There are more ways than one to skin a cat. Gonna take more than 2 hands to get the flywheel off without a puller and without damaging anything else. Get 2 heel bars and wedge and hold them 180 degrees apart against the back of the flywheel prying out. Then get someone else to hit the crankshaft as square as you can with a brass hammer. Once the flywheel is off, the only way I can think of cleaning up the threads where they are buggered up on the flywheel is to make a tap out of a sacrificial flywheel puller to clean up the threads. Hopefully you know how to do this.

I’ve never tried this tool, but I plan on getting it for future use. I think it would fit in there, though the crank end may make it useless.

ROTARY THREAD - Thread Repair File; Chase, Restore, Repair, and Clean: Male, Female, Inch, Metric, and Pipe Threads (RT1)
by RotaryThread
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Thanks for all of the tips. I think I will try to repair the threads. The thread file looks like a good option if there is enough room. I will try a pick 1st to see if I can get them good enough to get the puller to bite.

Happy New year and hope next year goes better than 2020. Interesting year...

If we're going to get Crazy here "just weld two heavy body shop slide dent removal tools to the flywheel at 3:00 and 9:00 o'clock and have a second person sliding one hammer slide while you slide the other.."

Where else could it go?

Yes, I'm kidding. I was never an employee of a butcher shop. This idea would work to remove the flywheel from the tapered shaft.

Here's my well used flywheel puller. I grooved it & probably tapered the first few threads a bit & it cleans out or cleans up damaged or dirty threads. I've shortened it a little once as threads were getting tired & was plenty deep so cut it back to good threads & re-grooved it.
with your flywheel if it were me '& without seeing it' i'd get in there & get rid of the damage so long as its only a few threads then make sure there's no washers left in there & screw it right home with puller bolt backed off. I don't use inpact air tools--well i do but not on this--i just screw the bolt up tight with a bar on it so its real tight with a holding tool in the slots to get a solid feel, then give it a good crack with a hammer. Never fails. Up to you of course & just throwing ideas out there.

Thanks for this suggestion..I have not had a chance to look at again..Been working on other things trying to get something to run so i can get a ride in someday. I may just have to intentionally cross thread it and get it in there enough to pull the FW off. I can see the the fly wheel has been pretty beat up . I can see it breaking apart where it goes on to the shaft.. Impact tools banging it to death..

Talking thread file & i've not used one for years but would the fact that its a left hand thread affect things--suppose not thinking about it & just scrapes one way from the sharp end.. Might be difficult to get it in there with the shaft in the way even with the nut off.

I had exactly the same problem with my XT500, eventually worked out that tapering the thread on the puller allows you to get to the good threads on the flywheel, added a pic so you can see what I mean. Get the puller in as far as you can, it took two of us and a lot of leverage on the puller to get the flywheel off!
Good luck and don't give up its a great feeling standing there with the flywheel in your hand!!

Thanks for this idea. I when I get a chance I will try this! Makes sense if I get the puller in there a bit farther I think I could get some bite, I need a win. My '78 Suzuki SP370 has a bad capacitor issues and runs really ad..My MX250 framed- DT250B powered machine has a Vape ignition system that I can't get timed right..and this DT3 flywheel problem...I will overcome!!

Hi all,
I got the flywheel off. I installed a PVL ignition system and I got a heart beat!! The original looks like it would need some work but not too bad.

I rigged up a puller and yanked it off using an impact tool. I dug up my PVL system I had packed away and did a quick install. Kicked it a few times and saw spark. yeah.. now I can try to get it to run.