rotten stringers

[tsubaki]

Welcome to the site!!
You'd be surprised how little the soaked foam will add weight to the boat.
We did a reno on an Ashcraft ripoff, convinced the boat was full of water in the foam. After 2 months poking holes, elevating and trying draining the boat we got only 5-8 gallons out of the inner bottom.
Primary consern would be the condition of the tank with the constant (salt) moisture, if it ain't smellin like gas it probably will be allright.
44mph with a 150 is goood, don't sound like no weight issues there!
Being you got foam, the stringer problem may not be an issue till you really need to get inbetween the two shells. BTW other than the wood in the bilge why do you feel the stringers are (should be) rotten? Normally they are surrounded with cloth and resin.
YES, pictures are expected!!

[macojoe]

Most of the stringers rot out right in the bilge cause of the sitting water there.
When the transom is done most just fix the rotted portion of the stringers and glass to the new transom.

You still can do the same if they not rotted to far under the floor?? Just use a screw driver and poke as far as you can reach, when you get to good wood thats were you cut off the rotted, attach the new wood along the side of the stringer and run to transom, using knee boards attach to the transom and you are good to go!

[garagenc]

I did mine (91 V20 350 I/O) what I did was remove the rotted wood (left the fiberglass sides) and filled the area with glass and resin, drilled and screwed the motor mounts in it with lag bolts.

So far mine is holding fine.