18sf performance numbers

fishfullthinking · #1 09-10-2011, 06:45 PM

Guys,

Trying to do more research 18sf and have few questions:

1. What kind of performance numbers are you getting on your 18 running 115, 140 suzuki and 150.

2. Do these boats need trim tabs?

3. How much water do they draft?

4. What is the fuel burn with 150 cruise?

The brochure on the site is very helpful with other questions I had.

Thank you,
Fishfullthinking

Bigshrimpin · #2 09-10-2011, 08:56 PM

18sf does not need trim tabs. You want a lighter weight motor . . . even with a 25" transom. Fuel burn with a 2.0L 150 Merc is 3 - 3.5mpg depending on your speed/load. There are lots of reports of 20sf's with a 140 zuke of 4.5 - 5mpg cruise with a top speed of approx 40mph.

2.0L 150 with 17P prop tops out close at about 38/40mph
2.4L 175 with a 19P with top out 45/46'ish.

Performance is very close to the 20 . . . actually I got faster speeds out of my 20 seafari with a bracket over the 18sf.

fishfullthinking · #3 09-11-2011, 04:19 PM

Thank you for the info. I am wondering if I can re-use the trailer from my mako and if it would clear my garage height wise.

Do you guys think it would be underpowered with 115opti which I currently have on my Mako or I would need to get 140-150 to get good performance.

Thank you,
Fishfullthinking

Snookerd · #4 09-11-2011, 04:20 PM

Tabs not necessary, they draw around 12 inches. First of all, it's all a trade off. Do you want the deck to self bail? If yes, then you have to have a wet weight of no more than 405lbs. A carbed 150 seems to be a great power package(it is self bailing barely). 140 Suzuki is great power, but it will not self bail. I currently have a 130 2 stroke which is better for weight at 358 lbs with decent power and better fuel efficiency than a carbed 150. The boat performs better with a lighter motor FWIW. The best 2 newer motors for weight and power is a 130 Etec and a new 125 Mercury. Both hit the weight requirement. Potters and Trackers can handle a heavier motor better.

Snookerd · #5 09-11-2011, 04:22 PM

Quote:

Do you guys think it would be underpowered with 115opti which I currently have on my Mako or I would need to get 140-150 to get good performance.

Thank you,
Fishfullthinking

The 115 opti would be great on it.