Any nfo on a 1983 20' Superfish w/200 merc

[Blue_Heron]

I have an '83 20sf with a 96 200 Merc. These Seacraft Industries hulls are 8" longer and possibly a bit heavier in the bow than the Potter hulls.

As far as their durability, I would say it's just as good. As with any boat this age, you will want to check the deck and top cap for soft spots especially around fastening points for console, leaning post, T-top, and hardware. Also trim the motor up and stand on the cavitation plate and bounce up and down. If the transom has any flex at all, it probably needs work.

Merc engines are pretty durable, too. I'm not familiar with the Mercs older than 1990, but I think they were 2.0 liter blocks. In the early 90s they went to a 2.4 liter, then a 2.5. If it's got good compression on all cylinders and they're within 5lbs or so of each other, it should be fine. Just understand that the savings in first cost on an old motor will have a trade off in repair and maintenance costs. One other thing to check is the steering arm. If it's considerably rusted and pitted, it may be ready to fail. On the Mercs, at least the '90s V6s, you have to pull the powerhead to replace the swivel pin/steering arm, so it's bout a $1,000 repair unless you can do it yourself.

Good Luck,
Dave

[Snookerd]

One other thing to check is the steering arm. If it's considerably rusted and pitted, it may be ready to fail. On the Mercs, at least the '90s V6s, you have to pull the powerhead to replace the swivel pin/steering arm, so it's bout a $1,000 repair unless you can do it yourself.

That's what phatcracker saw last Summer on my 1991 pre-stainless steering arm on my 130 Yamaha. The arm snapped! Motor would not die though........

[phatcracker]

Thanks for all the info guys. What should the compression range be on one of these? The Merc is an 84. I plan to check compression before I buy. I also noticed some discoloration on the bottom of the hull large areas from front to back. Not really a bright white like the rest of the hull. Any ideas on that?

Thanks again!

[Bigshrimpin]

125psi - 130psi for a 200hp from that era.

[Blue_Heron]

I also noticed some discoloration on the bottom of the hull large areas from front to back. Not really a bright white like the rest of the hull. Any ideas on that?

If the discoloration you're talking about is light brown or rust colored, it could be tanin stain from the boat being left in the water. If that's the case, Zud cleanser is what you need. You can find it at the grocery store along with the Comet and Ajax cleansers. The difference with Zud is it reacts chemically with tannin and rust stains. So you will need to put it on with a wet brush or cloth and keep it wet for a couple minutes while it works. No need to scrub, just keep it wet till the stain is gone.

I used to keep a boat on a brackish canal and it would come out with tannin stain below the water line. Zud took it right off. Same deal on rust stains.

[phatcracker]

That makes sense as the boat was in fresh water most of it's life. Thanks I'll give Zud a try. I'm going to check it out one more time and either drag it home or forget about it... with gas on the rise like it is I'm not sure I need something this big. It is a nice boat so I don't think he will have a problem selling it.

[wavelength]

I use "Rust Aid" from Home Depot put it in a sprayer watch the color disappear then rinse.

[phatcracker]

Well I got cold feet and backed out... I have listed it for the guy in the for sale forum but can't figure out how to post pics???? Did the PayPal thing but no changes or anything.