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

phatcracker · #1 02-19-2008, 11:45 AM

I am looking at a 83 20' Superfish that has an older 200 merc with T-top and in pretty good shape. Can anyone give me an idea of what I can expect as far a draft, fuel burn and ruggedness of something that old? I know the boats are pretty sturdy but am wary of motor... The owner claims to be OMC certified and to have taken care of maintenance etc. Any insight would be helpful...

Snookerd · #2 02-20-2008, 01:29 AM

Ahhhhh, Harwood, ready to throw your hat in the ring??? I knew you were getting the SeaCraft affliction last Summer when you looked at my 18SF. Checkout the specs pages on that 20 here on the first web page of CSC. It won't draw more than my 18 which was around 12-14 inches. Bigshrimpin is one to discuss the merc motor. Send him a private message. The 83 era is rock solid. Good luck.

Blue_Heron · #3 02-20-2008, 08:25 AM

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

Bigshrimpin · #4 02-20-2008, 11:55 AM

What year is the merc? 2.4L motors came out in 1978. They are almost all chrome bore motors (except a few late 80's models) In 1983 they there were some improvements made to the 2.4L mercs . . . fingerports, moved the head bolts to the outside of the water jacket (insted of next to the sleeve), added oil injection in 84?, chenged to the 3 ram trim and tilt in 85. The motors are light (338 - 363lbs), fast and extremely durable if cared for properly.

To give you an example of fuel economy . . . I can cruise at 33/34mph burning a 9gph pushing a seafari. I'm running smaller venturi carbs wh-11's on a old 1979 vertical reed 200 (with a 3 ram trim and tilt and 175XRI bucket style cowling). The larger venturi carbs like wh-22's with the horizontal front will drink a little more fuel . . . 10/11gph at 4000rpm.

The weakness on the older mercs is
1. wiring (inspect closely especially stator and trigger wires)
2. oil injection (remove)
3. spark advance module/idle stabiliezer modules (remove both)
4. corrosion - but this is true on any 20+ year old saltwater motor.

Snookerd · #5 02-20-2008, 11:59 AM

Quote:

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........

Bigshrimpin · #6 02-20-2008, 12:03 PM

If you want a 3 ram style trim and tilt + mid . . . I have 5 of them

(all freshwater CA parts)

If the powerhead won't seperate from the mid with heat . . . then zip through the bolts with a sawsall and find a good adapter plate + new studs. Then use vice grips + heat to back out the cut studs on the powerhead.

Been there . . . done that on one motor . . . it's a PIA, but only b/c I tried to coax the powerhead off before attacking the bolts 1" below the base of the powerhead (with the sawsall) . . . had I just bit the bullet and done that . . . it'd have been a 1 hour job.

phatcracker · #7 02-21-2008, 04:13 PM

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 · #8 02-22-2008, 03:19 AM

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

Blue_Heron · #9 02-22-2008, 08:12 AM

Quote:

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 · #10 02-23-2008, 11:24 AM

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.