Restored 20 SF and Optimax 135 Performance????
 

What are your thoughts on a fully restored and lightweight 1971 Potter SeaCraft SF and the Optimax 135?

I'm restoring the boat right now and will be done in a few months. I'm strongly considering the 2.5L 6-cylinder 135 Optimax think it would be a good combination. The boat will not have a t-top and motor is hung on a 25" transom.

I'd like to see a fuel economy of 4.5 to 5 mpg or better.

You should be very happy. I have a 115 Opti on my 1969 CC and it performs very well.

Michael

Changed directions ..... I'll most likely install a new Mercury 150 4-stroke on the 20 SF.

Weight of 150 vs opti?

About 25 lbs more for the new 4-s

repower
 

I would look at the 140 or 175 Suzuki. Great engine good fuel burn

The Mercury 150 weighs 455lbs. The Optimax 135/150 weighs 440.

The Suzuki 115/140 are about 410-420.

I am also considering the Etec 115 at 400lbs and the Optimax 115 at 380 as well as the new Mercury 115 4 stroke at 370lbs

As you can see, I'm all over the place 😊

If I was confident that the 20 SeaCraft with a raised deck (+3") and a raised transom and Nidacore floor could handle the weight of the Mercury 150, if probably go with it. But if the Seacraft won't plane under 18-19 mph with a 450lb motor on the transom, I'll find something lighter.

Thoughts??

My vote is sub 400 lb. 115 etec or merc. And some extra anchor chain for trim.

That v6 135 merc is a good motor for that boat

I'm almost dead set on the new merc 115 for my potter 20 when its done. Lighter than an etec 115. In fact, lighter than I think all the 115s. I had considered yammy 115 but the 2.1L displacement of the merc makes me think itd have more torque than the littlle yamaha at 1.8 liters and a tad heavier. For me it's coming down to the merc 115 or etec 90. I have an etec 90 on another boat and it's a fabulous motor, but I'm just not certain itd be enough for ME on my SeaCraft. I know others have the etec 90 and swear by it but I think I'd want a bit more.

Im running the etec 115 ...... unrestored it is heavy .... I think after the transom is raised it will be great !!! but I am still having issues with propping and my mechanics thoughts on rpm I should be able to achieve ... currently I can only turn up 5400 - 5500..... turning a 15 x 17 old 3 blade ... I think I am going to drop to a 14 3/4 x 15 4 blade in the near future...

My mercs 115 4s pushes my 20 pretty well

I just installed trim tabs on my 18 complete resto I have a 150 etec running 3500 rpm at 34 mph and 4.6 mpg

Marks 1971 20 with the Zuke 140 4 stroke was by far the best riding 20 I have been on. No wet feet. My 73 20' with 2 stroke 175hp was way too much power.

Btw: that's me at the helm :p
Check it out --------》http://www.classicseacraft.com/marks20/index.html

I just bought a 150 Etec for my '83 center console. It's a little longer than a Potter and already has a 25" transom. I was looking at the 115, but the 150 was only 26# heavier and is arguably the "sweet spot" in the Etec line and the price was right.
As soon as I finished the raised deck on my Gheenoe, I'll install the 150 and post some results.