what do you think about this?

The trick here is you're taking the risk that both will have to be completely disassembled and rebuilt from the ground up. However, if they still turn over freely, they're PROBABLY not in too bad a shape and won't require complete rebuilds.
 
Flood ? What kind of water? Fresh, brackish,salt? Now long was it sitting in the water? I would do a complete tear down on the motors to make sure there's not crap inside.
 
I would go take a look and ask all of those questions ^^^ then take a good look over all the bikes. Most important thing here is that they turn over and shift through all gears.
 
neither one has been started. they both turn over freely and shift through all gears and everything moves freely. they both have fresh fluids but i may change them again to be sure. it was a flodded creek so probably dirty brown maybe silty water. I dont mind doing work to them as long as it hopefully wont cost a lot. Can a 85cc be bored out to a 121cc im not sure? If anyone knows please say so so i can be sure hes telling the truth. I dont know if it would be the stock jug or a big bore jug.