Soft floor

[tbone]

I have a 91 supra comp. The floor is soft on the back left side by the gas cover. I have heard horror stories about floors and stringers rotting out. Someone told me to try to turn the engine mount bolts and if they didnt spin the stringers were probablly fine. Is there any way to tell if the floor is naturally soft in that spot or if the floor is rotten or the stringers are bad?

[SupraNut]

The floor feels soft because when you put weight on it, it deflects. It should not do this. Good chance it is rotting from below. As for the stringers, I have also heard about the bolt test and it makes sense except that it only tests the area around where the engine is mounted. The stringers extend the length of the boat. Unfortunately, the only way to investigate is to remove the floor. I had my floor replaced professionally in '03 and they said the stringers looked as good as new...hopefully the same can be said for yours.