I looked at a 2002 29 Fountain w/about 85 hrs on it.
Ran it on a hose. the 575sc sounded incredible.

Couple of questions:

I noticed there was a fair amount of black under the swim platform -Seemed a little excessive.
Does anyone know if this is normal for a 575sc? or normal for a Fountain due to the cavern created by the swimplatform?

They're asking 80k. NADA didn't list this motor.
Does 75-80 sound like a decent price for a 29 with a 575sc with 85 hours?

Anything I should look out for?

the black is soot from running rich. I had the same problem with my 525 and got a free reprogam from Merc. Get the engine's serial number and call them to see if there is a computer/ECM update for it. In fact try to get its whole history, outdrive included!!! I don't know if the headers had the same issue with cracking as they did on the 525 so you might want to check that out too. Just pay the money for a surveyor! I learned the hard way. Also the 575 should be a raw water cooled machine, so if it ran in salt vs fresh, that would make a difference. There's no real way to tell if it was flushed CORRECTLY if it came from salt. That's about all I can think of other than pulling the dipstick and looking at the oil. A milky color will indicate water, which indicates head gasket problems most likely. Get a sea trial!!!

Every Fountain I know of has the dreded black transom. My blown 27 had it, my 502 32' has it, a buddies triple 525 SC has it ........

My boat gets a dirty transom in under a min. at idle rpm's while sitting in the slip with the exhaust going out the drive.

No comments on the rest of your questions

I will get transom soot with HP500 as well. I wouldnt describe mine as "black" , it is a fine residue left after a day of boating especially if idleing around with the thru hulls on.

here's a pic shows the soot at the water line.

Transom soot is typical and normal.

As long as it is not real bad I wouldnt worry about it. It is better a whisker on the rich side than to be to lean! Just cary some swipes with you. jamie / lakeside

Thats about what I am seeing too Socal. A good coat of wax on the transom sure makes for a easier clean up..

Thanks for the replies. I'm looking forward to a test drive. -hopefully before new years.

Hey no need to rub it in that you will be boating in Dec.!!!