115hp in a 16ft.......Is this too much?

[silverking]

Hello,<br />Im lookin fo some feedback.....I purchased 3 weeks ago an excellent maxum 16´boat that came with an 85hp Force o/b,everything is working well and the hull is pretty good.<br />Actually I have a Cobia boat with a 96´ 115hp Mercury and im planning to change the motors and sell the Cobia.<br />My question: The Maxum claimed max hp is 85,I already swap to the 115hp and that thing is ready to takeoff. Would this be too much?, Is the integrity of the boat on danger? What to minimize the risk?...Any advice would be appreciated

 

[Pursuit2150]

Re: 115hp in a 16ft.......Is this too much?

1st Q=Yes,2nd Q=Yes, 3rd Q=Do not exceed max HP rating!!

 

[silverking]

Re: 115hp in a 16ft.......Is this too much?

Thank you Pursuit......I´m going to insist: I already put the Merc115 on the maxum and it´s really fast (50-55mph according to speedometer).<br />I like the way it runs, but Im affraid that something could be broken or worst: any of my friends or I can be injured.<br />¿Is there any trick or something to do in order to increase the power management of my boat?, Im reluctant to keep the Force and honestly the mercury is almost like new.<br />Please, I want to keep it!!!!!!!!!

 

[crab bait]

Re: 115hp in a 16ft.......Is this too much?

i guess you'll keep askin' till someone gives you the sugar-coatversion of the answer.. the one you want to hear.. then maybe it'll put your mind at ease when your runnin' around with friends & loved ones... but the answer is still the one you already know it is from the jump....

 

[silverking]

Re: 115hp in a 16ft.......Is this too much?

Ok Crab Bait, maybe you´re right (actually YES), but I want to know if theres something to do with the boat to increase the power handling.<br />I was thinkin on put 3 or 4 layers of Fiber Glass on the rear to increase stern thicknes and maybe put a reinforcing bars from side to side or in angle..Is there anything better to do??, and also, if i do it: Is that a legal violation?, If i dont have a better option i would have to sell the Cobia/Merc/Trailer and also trade the Force to buy a Merc 85 or 90hp..I dont want to expose my wife or friends just to save some money...Thanks!!

 

[JB]

Re: 115hp in a 16ft.......Is this too much?

Howdy, Silverking.<br /><br />Putting a bigger, more powerful engine on a boat than it is rated for is not like stuffing a small block in a 30s Ford.<br /><br />Your boat is rated for the torque and thrust of 85hp. Too much makes it a dangerous boat even if it doesn't rip the transom off.<br /><br />Pursuit and Crab Bait are right on the button.<br /><br />If you truly appreciate expert advice, as you say in your first post, take theirs. Be safe and be legal or upgrade your life, liability and boat insurance.<br /><br />Good luck.

 

[silverking]

Re: 115hp in a 16ft.......Is this too much?

Ok!!, thanks for the advice; I´m going to sell the Cobia and trade the Force for a Merc85hp or maybe a 75hp (if i got a good deal).<br />Once again, Thanks!

 

[Jango]

Re: 115hp in a 16ft.......Is this too much?

Take a look at the following US Coast Guard website covering Safety Standards. If your boat was a home built you can calculate the Max. HP.<br />According to the Manf. Info the 115 MERC is about 30 lbs heavier than the Force 85 (287 lb vers.255)<br /><br /> http://www.uscg.mil/d8/mso/louisville/WebStuff/comdtpubp16761_3b.pdf <br /><br />This may help you with your decision

 

[what200]

Re: 115hp in a 16ft.......Is this too much?

I'll tell you what you want to hear.<br /><br />What do you want to hear?<br /><br />Actually I feel that one of the bigger drawbacks of overpowering is the liabllity and insurance issues that you take on. One way to fudge for example would be to take an inline 90 cowling and transom clamp and throw it on an inline 150. Even your insurance agent would be hard pressed to tell the difference. But since your max is 85 I can't think of any motors that you can do that with.

 

[skier]

Re: 115hp in a 16ft.......Is this too much?

Here is a look on the bright side. that 85 Force is rated at the crank. At the prop it is more like a 75. If you get a 85 Merc you will still get more power than you had before.<br /><br />My 16' Glastron is rated for a 120 hp and it has two steel rods from the transom to the bow (I guess for the added stress)<br /><br />As far as changing cowlings, I had a 1979 Merc 115 and had a 1979 Merc 140 block swap, which ment that I kept the clamp, leg, lower unit, and cowlings. Even if someone does run the numbers, it comes up as a 1979 Merc 115. Only difference is that I have the same output as a newer 115 and maybe a few extra ponies for good measure.<br /><br />Craig

 

[jasonnb]

Re: 115hp in a 16ft.......Is this too much?

What200, I think a V4 Johnrude would do that if so inclined, but I would not advise overpowering. Take into account the wear/tear on an older boat. Repower with a newer 85 hp an pick up a few ponies without the hassles and safety issues. Then again, I'm nervous by nanute...

 

[SeaHorse]

Re: 115hp in a 16ft.......Is this too much?

According to the Coast Guard Guidelines my boat should have a 5 hp motor. Since it has a 25 hp (a big 36 cubic inch one at that) I better keep away from the Coasties We here in Deeetroit have always said "There's no substitute for cubic inches!"

 

[sho305]

Re: 115hp in a 16ft.......Is this too much?

I just put a transom in a 16' Bayliner. It has one 3/4" board instead of the usual double thickness of 1.5". Also has a 1x4 stringer on each side in the floor. Not much boat there, and that is why it is rated for a 90hp.<br /><br />I have a '73 Checkmate rated for a 150hp and it is a 17'. It has a 1.5" the entire transom not just 18" wide of 3/4" wood. It also has a horizontal beam across the transom just under the motor bolts and heavy matting.Not knowing about the stringers, but getting airborne at 54mph on that wake I missed would be scary without a good hull.<br /><br />Another issue is the handling of the boat at speed. Many people get hurt due to this as they are flying around in the boat. I have seen it first hand while aboard my friends 28' Challenger at 80mph on lake Michigan. Running around 60mph with the trim down we could cut 4-6 footers easy with this deep vee hull. Others could not and got into the hospital. Sometimes we would quit racing others when we could see them getting way out of shape and way stupid. <br /><br />A hull with a pad will go faster trimmed out, but will hit harder when it lands too. Lots of newer boats have pads now, and I think that is why motors come with those stock props that you cannot trim much...to help keep the idiots in line. On my little 130 acre lake, I can get in the air easy with my 17' and old 150hp at 50+mph. Just a wake from another boat will do when trimmed up good. Funny thing is I just looked at an old 15' 150GT Glasstron? with the same motor and it said 90hp on it.

 

[silverking]

Re: 115hp in a 16ft.......Is this too much?

Well, Well, Well......<br />Thank you very much to all of you guys who share experience and opinions with me.<br />This weekend I was looking around in my local marina and saw a guy who was modifying a boat : He was cutting the rear of the boat in order to make space to put not 1, but 2 Yamahas 90 hp on his Starcraft 18´Aluminum boat (je,je,je) I think that all his investment will go directly to the bottom of the lagoon if not when launched then when he skeeze the throtle.<br />I think he´s like me and expect a lot from his boat.

 

[RICKRICK1]

Re: 115hp in a 16ft.......Is this too much?

Silverking,<br /><br />One of the guys at work has a 65hp suzuki mounted on a 16' flat bottom john boat, 47mph on the water, jumps about 6' out of the water every time he hits a wave over 6 to 9 inches. He is into speed and he gets it, I rode with him once and once was enough.<br />You find a bathtub with 200 on it and he would have one.

 

[wallygator36]

Re: 115hp in a 16ft.......Is this too much?

I saw a guy DIE, he kept uping the power on his Boat....then one day it got loose...went out of control..... and Disintergrated....... in CALM water near the bridge...... remember..... you NEVER MASTER the sea.......you respect it.

 

[what200]

Re: 115hp in a 16ft.......Is this too much?

I have a boat similar to a starcraft aluminum boat that I threw a merc 150 on. It's a lot of fun but I didn't get the speed I expected and it must be respected for squirrely handling.<br />If I had it to do over again, I would just buy a separate speedboat to go fast in. I could spend a bunch of money on adding a pad to the boat but that would just make it unsellable. So in the near future I will probably just put a lighter motor on the boat and buy a hydrostream or something like it that is designed to go 70+. I'm not telling you not to overpower, but don't try to make it into a speedboat when it's not.<br /><br />BTW- I'm pretty sure that 2 90's is going to be real close to swamping that Starcraft coming off plane.

 

[495v]

Re: 115hp in a 16ft.......Is this too much?

I had a 16' Nitro bassboat that had a 125 Merc on it. The thing screamed, topping out around 70mph. Couple things, it's a bit scary doing that kind of speed in such a little boat. Secondly, too much power; the thing would start chime-walking at about 3/4 throttle. The boat was rated for 125Max so that's what I went with, but probably would have handled nicely with a 90 or 115.

 

[mellowyellow]

Re: 115hp in a 16ft.......Is this too much?

maybe it's just me, but when I'm on the water I'm<br />never in a hurry. I prefer to relax and enjoy <br />I'm not against speedboats, but there is little<br />tolerance for mistakes and we are human and feces occurs...<br />I'm just not that guy.<br /><br />PS. own a 71 Challenger 383 magnum, hurst 4sp.<br />but getting stranded on land is a little easier<br />to deal with and it can't sink (unless I drive it<br />into lake Erie)

 

[naughtybynature]

Re: 115hp in a 16ft.......Is this too much?

well you guys know what i'm going to say..... but i'll say it anyways!! hehehe i have always looked at power this way, buy as much as you can afford! you don't need to use it all, all of the time. but for those times when you are loaded down with passengers and all of their gear, you will be very happy you have the extra ponies. yes there a alot of boats out there that will do crazy things when pushed past their design limitations, however putting a larger motor on doesn't mean you have to exceed those limitations. once again it is the moron who does and that moron will probably learn the hard way. i'm not saying go out and put the biggest motor you can by on a small boat, just saying i would and do always put the biggest motor that the boat can handle (reinforced transom, full length stringers, knee braces etc.) then i don't have to use full throttle to plane with a heavy load, i can cruise at sane speeds with a fraction of the throttle needed by smaller motors on the same boat. remember, it's not the motor that makes a boat squirrly, it's the hull design. use the power sensibly and you will never get in trouble and you will be secure in the knowledge that you have the extra omph when needed. power doesn't have to just mean speed. use you head ladies and gentleman, and enjoy your boating... at 5 or 50 mph! <br /><br />i'll do mine at 100 mph hair straight back! hehehe<br />