I didnt have anything to do this week-end (it was raining like piss) so I cracked open my old engine.....the rear rotor seemed to have a bad apex seal and there was some deposits in the housing but nothing serious.....when these things blow, is it normal for them to scratch the housing....cuz mine looks fine...and the blown seal was still sitting in the rotor grove....its still stuck in there....lotsa carbon deposits on the rotor itself....i'm just trying to diagnostic the rotor/housing to see if it still good or not...

Sometimes the seal will stay in the rotor, thus preventing damage to the housing. Check the rotor housing for grooves and/or chrome flaking. Also check the water passages for cracks.

the rotor is fine and i just noticed some grooves around the oil injector holes....they're very small....tiny i should say..is it still good?

The apex seal that was damaged on my rotor was stuck pretty good. Since I was getting a new rotor anyways I pryed it out. It was really stuck more than I thought, plus the corner seal broke in half and one of the side seals was messed up.

It may be re-usable. How is the rotor?

the rotor has a lot of deposit on it....but overall seems re-usable...i'll have to take some measurement see if its near factory standards

The deposits can be cleaned off. That's normal. It's caused by injecting motor oil into the combustion chamber. When you tear down a motor that used 2 cycle oil exclusively it will look clean inside.