Okay. Weights for new 2018 motors, not left-overs.

Mercury 115 25" shaft is 363 lbs.
Evinrude 115 25" is 375 lbs.
Yamaha 115 25" is 383 lbs
Honda 115 25" is 485 lbs
Tohatsu 115 4S 25" is also 485 lbs
Tohatsu 115 2S 25" is 392 lbs
Suzuki 115 25" is 412 lbs

Top 3 look good for weight.

and the 3cyl ETEC 90 is 320 lbs

Drove over to BassPro in Destin to inquire about re-powering through them. They had the specs for this boat right there, seeing as it's a Tracker SeaCraft.

The 1988 18' Superfisherman is designed to carry up to a 465 lb outboard motor and still be self-bailing. The hull is rated for 150 hp max, and was designed to carry the heaviest 150 in production at the time, the Suzuki DT150CTX, which weighs 465 lbs.

In contrast, according to them, the previous year, which was also Tracker built, was only designed to carry up to 140 hp, and 370 lbs on the transom.

Ed said that although they only sold the 18' pre-rigged for Evinrude and Mercury/Mariner, they actually did sell two of the 18' hulls locally upon which the owners installed the DT150 SuperSick motors, but the "standard" power for this boat when new was either the Evinrude 110 hp V4, or the Mariner 115 hp I-6. Very few saw the Evinrude 140 or 150 loopers, or the Mariner 150.

He then offered to re-power my boat with a 2-year old left-over 135 Optimax counter-rotator for $10,200 out the door, including de-rigging my current power, and also offered me $750 on my running '87 115 Mariner as a trade-in, for a net $9650.

I'm a research nut, (you guys probably know that by now), but after all that, I think I still want a 115.

You might look at the G1 Etec 150 which I believe comes in at 425# or the new 4 stroke Merc 150. I run a 2004 Evinrude DI 150 on my 1968 19' Seacraft and its a very nice combination. 32mph cruise, 44 mph on top. great holeshot and economical. Mine is on a bracket though.

The irony is that Tracker can take credit for "the design" for 465lbs. when this 18 hull that came from Carl and Bill and they never built it for 465lbs.

The primary difference in this hull from mid 1987 when SIC ( 1980-1987)stopped producing was lighter cores and less glass (still a great boat). The 1987 boat that my family owns is a tank. It is too heavy for anything over 400lbs. - That is why Ed said that an 87 only says 370LBS -because it would sink like my parents did with a 400 lb 2 stroke Johnson 150! (Tracker owned SeaCraft half of 1987, and they were selling off the old SIC boats that Tracker never built) . The primary difference from SIC back to Potter was a better strength to weight ratio with fiberglass schedules on Potter boats AND the console is farther forward on SIC and Tracker 18SFs(that's the most noticeable design change). Under 400lbs is ideal for a Tracker, 465lbs is insane and is not self bailing, and 425 is do-able, but borderline.

Maybe I'm looking at the wrong numbers, but the Suzuki web site is showing the current "X" length DF140 at 405 lbs., with the same displacement (2044 cc's) as the 115. The only time I ran into wet feet problems in my '75 18SF/140 was when I forgot to fasten the washboards and tried backing down into a chop. I did put the battery under the console and kept the stern free of junk and big humans, but I don't recall ever coming close to sinking it. Good luck with whatever you wind up with... I'm still wrestling with the repower decision on my 23' Sceptre.

1987 18SF freeboard with a 140 Suzuki (the water line is 6” above the chine :(

Bmajvi-You're right the Zuke web site does show around 405. The DF140 25" weight has always been around 420lbs(I checked NADA for 2010, it's still 421, but the 2017's show 407???). Suzuki either cut down the weight or they are going to the Mercury school of "lowball the weight" to compete with engines that either weigh less or also lie!

Well this is getting interesting.
My `89 20 Slacker is rated for 235 hp per CG plate. The transom is 2 3/8" thick.

Padre, how thick is your transom?
Another vote for the smaller ETEC here.
The idle mpg is over 9 on Denny`s ole safari w a 150.