What hp engine for a 22'2" flat back

[Far67rar]

I am thinking of getting a 22'2" Flat back, how does a 150hp at say wide open throttle or 3/4 throttle compare to a 200hp at 1/2 or 3/4 throttle in the speed and fuel consumption department. Also has any one out there ever put a 90hp on one of these boats. I am realy not that concerned with speed

[fitz73222]

I really think that a 150 or 200 is way overpowering these boats. They were never designed for that kind of power or speed. This was a 30-35 mph boat. The nature of this hull design allows for more stern lift and more bow down which cause the inherent bow steer condition. Read in the photo gallery the 1966 Rudder article about how the boat ran with twin 55 Chryslers and her tendancy to bow steer with those enemic engines. The standard large outboard in 66-67 was 100-115hp. The boat was designed with the correct amount of stern lift for this engine size at 32mph. It is nice to have plenty of HP on any boat, but whats the sense if you can never use it. My 73` 22-2 has twin 115 Mercs, this is the 12 degree bottom. Looks nice, plenty of hole shot, etc ,etc. Runs 46 mph and will beat you to death in any kind of chop running that fast. I really wish she had twin 75`s or 90`s max. The boat runs great at 25-29 mph. I dont need 230 hp to do that along with 10 GPH @ cruise. Every boat has that sweet spot where it does everything well at a certain speed and trim. I think the 22-2 Flatback is a prime example of a boat that will do just fine with moderate HP and not benefit at all from big HP.

[GoneFission]

Ditto on the above - you can put a 200 on, but I think a 3 or 4 cylinder 125HP would be a nice match.  They weigh less than 400 lbs. so you don't have as much weight where you don't need it, and fuel consumption would be better as well.

[gran398]

Captain Matt is a respected SW Fla guide, in the process of a 22-2 flatback re-build.

http://www.captmattmitchell.com/

He has needs in terms of carrying the charter....some days, a lot of weight....A 150 Merc would get 'er done, on a daily basis.

The rest of us, I'm with Fitz and John....its a flatback, easy up, easy go...

A big torque four cylinder 2 stroke would be ideal.

Guess it all depends on need.

JMHO.

[LilRichard]

To answer the question, my (way overbuilt) flatback will run just over 40mph at full throttle with 2 dudes and 2/3 tank of gas.  As everyone else has said, these are not high speed boats, and anything over 150HP is diminishing returns and upsets the weight balance of the boat.  Let me restate that last line, IMO it's the most important part... these boats are very sensitive to weight in the rear.

I picked a 150 Suzu because it was one of the lightest motors (except for Etec and Opti) and the lightest four stroke in that class.  I think you would be pleasantly surprised by how well it runs.

[Far67rar]

Thank you for your input, I plan on finding a hull and rebuilding it. I think every thing (Console, Hydralic steering, etc.) off of my 17.5 will work on a 22'2", I am thinking about trying my 90hp on it for a little while. I am not that worried about speed I spend most of my time around 24-29 mph now. Its my favorite type of engine; paid for

[gran398]

Good deal!  Run that 90 Tohattie... or Yammie...  or Merc..... or Johnnyrude.... 'till she croaks. The purists around here are all about it, nothing wrong with practicality. And when the others blow up...as a friend would say.....

"See ya on the water".

[Ben87]

This boat originally came with an 87 BlackMax 150-HP.

 

I had it repowered in 2006 with a OptiMax 150-HP.  I'd say it is the perfect motor for the boat though a 175-HP would have been nice, the increase in price for the performance wasn't justified.  

With an AL 3-blade Mercury prop, 15x17, the boat would run 45 MPH @ WOT.  

With an AL 4 blade Mercury prop, 15x16, the boat would run 42 MPH @ WOT.

Both got the same 30 MPH cruise at 4,000 RPM.  

The boat gets right around 5 MPG with the OptiMax.  

Of course, this is an 87 222 Opsrey and not a 22'2" flatback/bracketed boat.

[Far67rar]

Thats good information thank you; and nice boat

[gran398]

A stainless prop would probably kick her up 3 to 4 mph.

[Ben87]

The boat is now used my my sister and her husband. They are pretty much newbies at boating.  Last summer-early fall, my BIL put the boat up on some rocks and dinged up the skeg and the prop pretty good, thank goodness the motor had the AL-prop on it.  He spent about $75 and got it fixed up perfectly.  

I'm sure with the spare S/S Mirage Plus 15x17 I have, the boat would fly at the top end and every where else.

With the 4 blade AL, the holeshot is incredible, of course, I'm comparing it to my heavy Dusky, but it pops the light 222 right up and on its way;



I know that no matter what the load I've carried in the Aquasport, 6-8 people, full fishing gear and food, I've never had an issue with the 150-HP motor pushing it at all.

[Far67rar]

Has anyone out there ever put a 90hp on a 222 flat back. Its a 2003 90hp 2stroke Murcury.
Any idea how fast it would go or how much fuel would it burn. How about prop size.

[GoneFission]

I think you need at least 100-115 - but try it out - maybe that's enough - put 3-4 people on board and see how she does...

[RickK]

I drove a FB with a 90 on it and while not a speed demon, it was fine.  Unlike a normal planing hull which you have to overcome the "wave" that you are pushing ahead of you until you "jump up on plane", the configuration of the FB seems to just start pushing through the water and then keep going faster until it's on top of the water - they don't jump up on plane, so the 90 "pushed" it fine.