If you havent rejetted a big bore, it is really a crapshoot. If you simply do the overbore and size the head out to have a pretty stock type of compression ratio and combustion chamber shape, you would need to lean the critter down to make it run right. When you do as you have, and lots of us do, reshape for a different dome shape on the piston or change ratios, or change the port timing more than just restoring it, the jetting my change.
Some find you have to jet fatter just to get it to start as easily as before. For me, I do the chicken jetting and either stay the way I had it, or jet up a little. So far I have always been rich on the two strokes (not always on 4 strokes though).
what did you do with the ports on this one?