What size outboard would be best?

[Gman 82 aquasport]

Newbie to outboards, I have a 82 Aquasport center Console 20 ft, 45 gal fuel tank in floor,no motor on it(redoing hull), it's rated for max HP at 185, so what would be a good all around motor size to use on this. We will be doing some offshore fishing as well as lake run around. No more than 15-20 miles off shore max.Is 115 hp to small or should I look at 135-150 Hp. I realize that more HP means less economy. Any input is appreciated. Going 60 MpH not important but would like to get up to 40 MPH on smooth water. Hull weight is 1550 lbs.

 

[Home Cookin']

Re: What size outboard would be best?

I'd say 115 minimum. 150 is a popular engine so it may be easier to find one.
My 21' CC barely does 40 with a 150 at WOT and I don't like to run WOT in part due to fuel. It cruises comfortably between 28-32. So I think if you want a cruising speed of 40 you want a bigger engine (I'll get you my boat weight later).

But you have a 45 gallon tank; mine is 80. Consider, then, your range with a smaller tank, and larger engine, than is paired with a fairly generic rig (mine) matching a 150 with an 80 gallon. So look at the charts for your GPH to see how many hours you get out of 45 gallons.

The old Aquasport CC's are good solid seaworthy boats. A friend has one from the 70's and recently repowered it. Does right well in skinny water similar to your inshore areas; I thnk the V must not be but so deep.

 

[Gman 82 aquasport]

Re: What size outboard would be best?

Good info, unfortunatly the boat came with the 45 gal tank so I will make do. I was thinking 135-150 hp. The 150's are fairly easy to find around here(lake motors). I don't need it to run 40 all the time , cruising at 28-32 would be about perfect, with 40 a wish at WOT. 115's are easy to find also but I have a concern of being under powered...

 

[dingbat]

Re: What size outboard would be best?

I would go with a 150 - 175HP.

It's not about speed, it's about having the power when you need it. Running, or should I say plowing your way 10-15 miles in a following sea would not be pleasent experiance with only 115HP on the transom.

A newer 150HP 4 stroke would get @ 4-5 mpg on that boat. With a 45 gallon tank, you're looking at 180-225 mile range.

 

[JB]

Re: What size outboard would be best?

70% of the rated 185HP would be 130HP. That is the bare minimum I would recommend, but for an offshore boat I would put a 150 on her, Gman.

Bon Voyage.

 

[Silvertip]

Re: What size outboard would be best?

You would likely find that a small motor running near wide open to maintain a reasonable speed may actually consume the same or MORE fuel than a bigger engine that is "loafing". Just because you have a bigger motor does not mean the throttle needs to be wide open all the time. It is reassuring however to know you have the extra power if needed.

 

[Frank Acampora]

Re: What size outboard would be best?

Get the 150! A 115 just is not going to cut it for any kind of offshore. My 20 foot cuddy is running a 140 with a 30 gallon built in. With a 115, I doubt if it would break 30 MPH and while you don't really care about top speed, the extra power and speed in reserve is a good thing to have.

I carry a couple of extra tanks if I intend to put mileage on it.
If you figure about 2 MPG the 45 gal tank will get you out and back, but with little or no reserve. So a couple of 6 gal tanks for reserve would be wise. They usually don't really get in the way either.

 

[Gman 82 aquasport]

Re: What size outboard would be best?

Thanks for all the info, I will be looking for a 150 hp, not real brand specific(no force) nothing made before 1985 if I can. Doing this on a budget. I should be able to find a 150 2 stoke around NC for $1300- 2000... depending on year and hours and if it's been gone thru. Most motors I have looked at on sites have contols and harness, but I
will have to probably change out to binnicle controls, no big thing. After I get it finished I will try to post pics of before and after....I bought about hull and trailer 1 month ago for $700...

 

[RRitt]

Re: What size outboard would be best?

personally, for offshore, I would prefer two smaller engines over one large.

 

[zpoolman]

Re: What size outboard would be best?

For offshore don't even cosider a single 115 on that boat. A 150 will work ok, 175 even better. In 85 motors were a lot heavier so weight should not be an isue. Twins are better but lots of $$ to buy and set up. I have a 21 Tropdy that had twin 125 forces, re-powered to a new yam 200 two motors were just to much. Good choice to stay clear of forces. Since that boat was rated for 185 it sounds like it was a boat that offered the OMC seadrives, I think the smaller seadrive was a 185. Your boat probable has a real thinck transome with a tank a little farther forward. If your doing that much work drop in a bigger or a second tank, you'l appreciate it. my trophy holds 120 wich is a stock tank for it, and my 23 ft Olympic holds 88.

 

[444]

Re: What size outboard would be best?

The general rule of thumb is don't go below 70% of rated max hp. However IMO it depends more on hull shape and weight. Go too small and you'll have to be heavy on the throttle to get where you want to go. Go closer to the max and you can pick a prop ratio to give you a comfortable cruising rpm and hopefully reasonable mileage.

 

[ezmobee]

Re: What size outboard would be best?

In 85 motors were a lot heavier so weight should not be an isue.

False.

 

[Brewman61]

Re: What size outboard would be best?

I hear way more comments complaining about being under powered than the opposite. Your wallet, but it's better (IMHO) to spend the bucks up front and be happy, than to go low, and be disapointed. And eat thousands of dollars if you decide that you want more engine after all.

 

[Gman 82 aquasport]

Re: What size outboard would be best?

In the mode of more is better ! I found a deal on a 200 Johnson (1994) and purchased said motor. My boat is rated for 185hp, will putting this motor on cause great problems or not. Weight between 175 and 200 hp is not that much. Transom was rebuilt 2 years ago and is solid. ..thanks

 

[ezmobee]

Re: What size outboard would be best?

Suffice it to say, you really don't want to ask that question on this forum.