Floor Repair on 71 20' Seafari

[MarkJ]

How would I go about repairing the floor where the seats mount to? It is soft only where the seats mount to the floor. The screws that hold the seat pull out with rotted wood on the threads. So I was thinking about cutting just that section of the floor out and replacing the wood if possible or could I glass in a piece of wood on top of the deck just to hold the seats in place. The rest of the boat is solid, I replaced the transom about a year ago.
Also I am looking for new Power and was thinking about a 2002 Suzuki 90hp to replace a 72 Evenrude 125 electric shift. Is 90hp enough power? Any advice would be great, thanks

[Bryan A.]

I would spend the time and cut out that section of the floor and put in a new piece of marine ply rather than glassing something on the top. If you take that route you still have the soft deck underneath. At the very least you could over drill the screw holes and remove as much rot as you can then fill with epoxy and cabosil or glass fibers.

As for the power I would guess way to small. I have a 20 SF with a 175 and the consensus here seems to be 115 about the lowest you can go for a 20. I am sure others will reply on the power.

Welcome to the site. Hell of a first post and project.
Pictures always help.

[nestorpr]

I also have one soft spot to repair soon so I wish you luck. As for power, I have a 140hp I/O on my Seafari and the boat could use a bit more oomph, maybe 175.

[oldbluesplayer]

On the motor question, I also have a 20' Seafari, '73, with a 115 OB, an older Johnson 2 stroke, - it performs fine, hitting 30+ mph on gps. I do think the 90 would be underpowered, though. It would get on plane with just 1 or 2 people, but put a family on it, with a full tank of gas, or try to tow a watertoy, and you'd be straining.

On the floor - don't do a bandaid approach, patching on top - cut out that section of floor, top skin, replace the core with marine plywood bonded in, and reglass the top skin back on - not really a difficult job - just sounds daunting if you haven't done this stuff before - but you did say you had already done the transom ??

As they say - pix most welcome - and welcome to a great web-site !!

Bill

[MarkJ]

Thanks for the advice!!
Yes I did do the transom so I found a used 2002 Honda 130hp I think I am going to go with that. Its heavier thant the Suzuki but I don't think it will be a problem with the new transom.
As for the floor I started cutting today. The rotted wood doesn't spread too far so I am going to drop in a peice of marine plywood and double up 2 peices of 3/4in ply to get a raise in the floor and taper the edges and mould it into the existing foor. That should also give me more wood for the seat base screws to hold better.