2005 yz85 issues

Hey everyone I'm having issues with my son's 2005 yz85 fouling plugs/bogging. We have had the bike for 2 years with no issues until we went to a race and he completely submerged the bike in water. We flipped it drained it, ran multiple cycles of new oil through it until the milky oil stopped coming out of the trans. Since then it keeps fouling spark plugs (6) after about 4 hours of ride time (plug is black and wet). There was also a new low end bog when taking off. I've tried adjusting the air screw and have dropped the needle down one clip (it's now in the first clip position). The bog is also very apparent when you blip the throttle 3/4 to full throttle. Things I've done since the submerge is:

1. Tested compression that was low and replaced with pro-x piston and ring.
2. Replaced oem reed valves.
3. Brand New air filter.
4. Removed pro circuit 296 forest muffler re-packed and cleaned.

I'm starting to think it's a stator or air leak issue. I can't however seem to find stator information for the yz85.

Any ideas or help would be much appreciated!