1986 SF repower
 

I am considering repowering my '86 SF. I have read the informative threads suggesting "Lighter is Better" for the classic 20's, but the '86 is a foot longer and I believe a fair bit heavier than the 70's boats. The boat currently has a 2005 Yami 4-stroke 150 which is a pretty heavy motor. The transom is rebuilt and raised for a 25"motor
1) The Suzuki df140 is about 75 lbs. lighter, I see this as a plus, as I have always thought the boat sits a little low at the stern.
2) Will I be happy with the performance of the Suzuki DF140 if I am used to the Yamaha F150?

My ‘79 MA runs a 1999 OMC 175 carbed but gets horrible fuel mileage.

My brothers ‘88 18 SF has had an OMC 112/115, then a fresh ‘95 OMC 150 rebuild. When that finally popped he went with a Zuke 140. Much better fuel economy but he only knows two speeds. And the 140 does not have the top end.

I think you would find the 140 slightly underpowered but that may be fine with you.

Recently sold a ‘77 20 Seafari with an ‘06 E-Tec 150. Man that was a great engine! Oh well. Tough choices. Better info to come along. Hope this helps.

Vezo, Part II

Good input, thanks. It is always tough to know what to do when the options are all pretty good.

I had a '08 yamaha F150 on my old waterlogged '78 20SF. She definitely sat a little stern heavy, would porpoise a bit before getting on a plane, and needed to stay in the mid-high teens to keep on a plane. top end speed was about 40kt.

Ive since ripped a couple hundred pounds out of the boat during my restoration and am trying to decide to what to repower with. I too have concerns with the DF140 not being enough power. ive been considering the mercury 200 (475 lbs). i know the old guard will say thats too heavy, but i've moved my tank forward a little over a foot, slid the console/LP forward 4 inches. also its no exaggeration to say i pulled 250 pounds of soaking wet foam out of the aft end of the boat. im hoping all this will allow for a heavier outboard

for what its worth, i've always been told the yamaha is 150+ and the suzuki is 140-

definitely not quite apples to apples

So...
Yami f150 - 487 lb.
Suzuki DF150 - 522 lb.
Suzuki DF140 - 408 lb.
Pretty compelling, both the 150's are heavier than my 2005 F150 that I think is a little too heavy for this boat. Top end speed is not something I get too excited about, as the sea conditions up here in MA don't give us too many opportunities to go wide open. If I can cruise at 30 knots that will satisfy the majority of my open water needs. Getting up on plane, and lighter weight on the transom so the boat doesn't sit too low seem like my biggest concerns. I guess you can tell which way I am leaning. Also, a significant money savings.

455 lbs for the Merc 150. Very strong 150 but doesn't offer fly by wire controls if that matters.