100hp on a 20 sf?

[seacraftks]

Hello I beleve its because there transoms are not redone a 150 yamaha would send your boat along around 55 plus Kts with great gas milage

[Bushwacker]

. . . but the concensus here is that less is ok- why is that?

The concensus is less WEIGHT is ok! Power can be whatever your wallet can afford! The 20' hulls were designed for motors that weighed ~ 300 lbs, so if you shift the CG way aft by hanging a 500 lb motor on the transom (or, even worse, move it further aft on a bracket) it WON'T RIDE like it's supposed to, and min planing speed will be in the low 20's instead of the low teens!

Most folks don't seem to realize how much more efficient the SeaCraft hull is compared to almost any other boat, so they don't NEED all the power you're used to seeing on other similarly sized boats. Carl Moesly got ~45 mph out of the early 21's (which are HUGE 21' boats) with just two 100 hp I-6 Mercs!

The 23's seem to run fine with a single 225, and the 20' hull will run fine with a light 85 hp motor. Ran mine for over 30 years with a 115 with no complaints, especially regarding the soft ride. In fact, the 20 will start to go airborne in seas over 3' above 20 kts, so if you run offshore a lot, you won't be using a lot of power. IMHO anything over 150 hp on the 20 is overkill! Maybe I'm spoiled because the E-Tec is a VERY strong 150 (actually 165 hp at prop), but I almost NEVER use all that power! The boat gets on plane easily at about 45% throttle (the I-Command gage displays throttle position sensor reading) and optimum cruise is about 37% with a very heavy Bahamas-cruising type load. Although it will run almost 50 with a light load, I rarely run more than 30-35 and generally cruise at 25-28 mph.

Another factor that reduces a SeaCraft's power requirement is the relatively light hull weight compared to other boats of similar strength. The early Moesly and Potter models were built like aircraft, with balsa cored soles and decks, with very tall and stiff stringers that were relatively thin but installed about half way through the layup and finally bonded to the inner liner, essentially creating 4 very stiff I-beams between the cockpit sole and the bottom. (Ask the guys who have pulled out the inner liner just how tough these boats are!) Hope this answers your question!

[Fr. Frank]

The concensus is less WEIGHT is ok! Power can be whatever your wallet can afford! The 20' hulls were designed for motors that weighed ~ 300 lbs...

Most folks don't seem to realize how much more efficient the SeaCraft hull is compared to almost any other boat, so they don't NEED all the power you're used to seeing on other similarly sized boats.

I have rigged new 20' Seacrafts with only 70 hp, and they did just fine. 85/90 hp and 115 hp motors were the standard. The original hull is designed for 300 lbs OR LESS !!

[eggsuckindog]

IMHO opinion 150 is perfect - less weight the better, 4S is just usually too much except the zuke 140. Will a 130 work sure, will a 100 get it on plane ya, doesn't mean the boat works as well at planing speeds. Its not all about WOT, the extra power makes the boat work better at low speeds and cruise. Getting the hull to ride higher on the deeper vee is what its all about - low HP will not do that, they slog like everything else, not why you buy a SeaCraft. It is a high performance hull and needs X amount of HP to work as designed - just say'in.

[Mark]

What kind of #'s are people getting from the 140 suzuki's

41mph at WOT with full 75 gallon tank in calm water, boat with t-top. 26-28mph at 4,000rpm, same load and conditions.

[DonV]

The "ESD" is correct.....It's not all WOT. It's how it performs with a load of people, tackle, fuel, coolers, ice, etc. Does it get on plane properly?? Run well in all sea conditions, even emergencies?? Provide optimal fuel mileage with little strain on the engine at cruise??

I've been at WOT once, however was not able to catch a single fish.

[Fr. Frank]

I've been at WOT once, however was not able to catch a single fish.

I caught a fish at WOT once. Dam..d flying fish flew out of the water and smacked me right in the chest. Actually I didn't catch it, it bounced off and landed on the deck.

[FishStretcher]

Any opinions on the Yamaha F100? There are a few available on Craigslist used. And ther are 356 lb.

Looking for modest reliable performance. 4 stroke is a must.

[Yz2009]

Ive got a 99' F100 and its a great motor. Only thing is dont let gas sit for a long time in the carbs or it will get gummed up and they will have to be cleaned. The only issue ive ever had with it, is the voltage regulator went bad last season. So 11 year old motor and only issue to date was a voltage regulator. Always starts first crank as long as youve got good gas.

[Mark]

Looking for modest reliable performance. 4 stroke is a must.

You just described SUZUKI