18' Superfisherman performance

[Fr. Frank]

I've finally put the 18' in the water. It has a 1987 Mariner 115 hp motor, with under 200 original hours. I put a 4 blade Turning Point aluminum prop on it, 17" pitch.

The 1987 115 inline 6 cylinder is the same motor as the old 140's, right down to the size of the jets in the carburetors. We tried to put it on the hydro-dynamometer, but had to look at the gauges, as the computer interface wasn't working, and the printer was out of paper. It appeared to be producing about 123-125 hp at the prop-shaft.

Auto-Blend oil mixing is disabled and removed, running on 5-:1 premixed fuel. There are no trim tabs, but I will be adding Sport Tabs later because Choctawhatchee Bay is frequently very choppy.

Hole shot is very impressive, at just over three seconds. Very little bow rise with the stern-lifting 4 blade prop.

Best cruise seems to be at 3700-3800 rpm and 25-27 mph.
Top end is at 5800 rpms at about 41-42 mph.

Overall, I burned about 8 gallons in just over 80 minutes and traveled 31 miles according to my GPS, with an average speed of 17.8 mph over the entire time, for an average of almost 3 mpg. That actually surprised me, as I was expecting a fuel burn closer to 2.3 mpg based upon owning many inline 6 Mercs over the past 40+ years.

I'm looking at/considering repowering with a new or NOS motor in the 90-150 hp range. So far, I'm leaning toward either a Suzuki 115/140, or a Mercury 4S 115EXLPT Command Thrust or 150EXLPT, both of which can be found as NOS leftovers in the 2015-2016 model years, with a purchase price of $7600 to $8100 for the Zukes to $8300 to $8500 for the Mercurys, not including rigging, controls, gauges, or props.

I leaning toward these motors mostly because of price, because the Etecs are 2017-2018 model year only for an extra $3K, and because Yamaha now wants you to replace the flywheel/balancer assembly on 2014 and newer motors inline 4 and V6 motors every 80-100 hours because of known failure issues, and it costs over $900 each time.

If anyone has simple data on the Zukes and Mercs, let me know. I can't buy the motor until July, though, as I'm taking a sabbatical trip to Israel in June, and have to pay for that first!

[ericallen01]

Note the weight change from 315 lbs to ~375 lbs with the Merc 115 - I have a 90 yammie on my 1979 and it just (barely) drains when I put an extra 100 lbs on the engine. Might be different if it's an '80s 18SF

[bmajvi]

I put a new Zuke 140 on my old '75 18SF in early 2002, and sold the rig in '06 (and have regretted that decision ever since). Lotsa motor/weight for sure, but crazy quiet, powerful, and 100% reliable. We didn't prop it for top end, as she was mostly used in the ocean, so maxed out at 41-42 mph on the GPS in flat water. Good hole shot even with 3-4 people onboard, and wonderful mid-range power - really great for shooting rough inlets, kind of like skiing between the bumps! I used to run it all over the USVI and BVI, and would average around 5 mpg on a full day of mixed use, which made me smile a lot! Snookerd's folks put a 140 on their 18 and he says they love theirs too.

[Vezo, Part II]

Vezo, Part 1 has an ‘88 SF, original OMC 112, then a rebuilt 150. Loves the boat so much he pulled the trigger on a Zuke 140 4S. Lost some top end, but sweet. I think he has @ 650 hours and Happy. Nice rig.

Back in the early 2000’s we ran my MA OMC 175, along side his OMC 150 through the gallery of boats on Sunday of the Heritage Golf Tournament, outside Harbortown and the 18th hole. Blimp shot the almost twins running just shy of 50 mph. Must have been a lull in the action. Fun s#it.

Vezo, Part II

[Snookerd]

Fr. Frank-I have owned an 87 (150 Johnson and 140 Zuke),88 (130 Yamaha), and 89 18SF(130 Yamaha). I had the 89 when I met you at the Anclote gathering.

Your 88 with the 140 Suzuki is doable. My parents 87 currently has a 140 Suzuki on it. It is too heavy on the 87. But.....the 88 is a Tracker with a different and lighter layup schedule of fiberglass and it can better handle it. At best, it will be borderline self bailing. I would recommend a 90 -115. There are some very light motors from etec to Yamaha's new 25" 115B at 386lbs. After seeing Terry's mighty 90 Etec, I would lean that way for the lowest weight.

[Fr. Frank]

Originally Posted by Snookerd

Fr. Frank-I have owned an 87 (150 Johnson and 140 Zuke),88 (130 Yamaha), and 89 18SF(130 Yamaha).
I would recommend a 90 -115. There are some very light motors from etec to Yamaha's new 115B at 375-400lbs. After seeing Terry's mighty 90 Etec, I would lean that way for the lowest weight.

I'm going to look into that right now...

[erebus]

I just priced out a 115 Suzuki from International Marine in Florida for a customer, and shipped to us complete with all needed rigging etc, was about $8600.
You would of course then have the labor of rigging it either by a yard or by yourself.

Oh and an extra $150 if you want it in white.

[Fr. Frank]

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

[Fr. Frank]

The hard part is waiting to get a new motor, even though this old Tower of Power runs very well. I haven't purchased a new motor since 2006, when I bought the 90 Optimax to put on the back of my 2-boats-previous 20 Seafari, the Fishalot III.

My local Evinrude dealer is going to see if he can get one of the several left-over 2016 E115DPX motors another dealer has up in Illinois. No definite word on price yet, but he thinks he can get the purchase price under $8K, not counting controls, prop, and a tach with idiot lights, and sensor harness for NMEA2000, or about $9K to $9.5K out the door including tax and rigging, (assuming I bring it ready to rig).

[Beaver]

Just a thought...Have you looked at the Tohatsu 90? Low pressure fuel injected 2 stroke that gets fantastic fuel economy. They're suppose to be super reliable and they're super light. I keep seeing them advertised for about $7300 new (which includes rigging). When my current Tohatsu 90 gives up the ghost I think I'm going to go this route.