Your input on Outboards
 

Just a thought and asking your thoughts.

Love my 29 Outlaw, the layout suits us, we overnight on the boat so we do use the cabin, size is just right for our needs, and I love the exhaust note of the motors. The one thing I don't like is the fuel mileage.

What do you think about hanging a pair of state of the art outboards off the back? From what I see,
outboards should get about 3 mpg where I now get 1 mpg.

We would also gain a huge amount of storage and be able to enlarge the cockpit.

Do you think the boat would still handle right? Would this screw up the CG or something else I'm not thinking about to the point of ill handling?

I'm lucky to have what I have and don't really want to buy something else, and I haven't seen anything else in a outboard boat that I like.

When we boat, we like to drive, not just sit in a cove and read a book. With the cost of gas (and I think it is only going to get worse) I'm finding myself thinking twice about going from Havasu to Topock just for the hell of it, or going out in the Pacific just to find Dolphin, or going around Catalina Island because we can. I hate that the cost of fuel is making me think twice about using our boat the way we like to.

Your thoughts!

I think you are talking a lot of work, expense, and creating a very "unique boat" that may destroy resale value. There are options out there including center consoles that will achieve your goal. I'm curious tho, do you have big power in the 29 OL because with stock standard power you should be achieving 1.5-up to 2 mpg with them? Another idea is to be sure to be running your boat at optimal efficiency and even prop changes can drastically increase cruising efficiency.

how did you come to this conclusion?? and how do you only get 1 mpg with a 29 ft boat? what power do you have now?

If you want mpg get a pair of Yanmar 6LP 315 hp each

Did someone say O/B's :whistle:

Personally I think it would be a way cool project.
I agree on re-sale being a variable but I think done right, you'd be fine. W/the newer O/B's they're not the bad word to average boaters that they used to be.

A pair of 300 Xs Mercs would be killer on their. They're great motors and very efficient.

I can tell first hand that my 24' Sonic has the space of a 30' I/O boat due to the clip ons, and them being on a bracket.
Your boat would be GYNORMOUS!

The motors are nothing fancy. Merc 330's.

Ok, so it's just a WAG on the mpg.......but am I wrong to think that outboards would at least double mpg over big block v8's?

Keep the input coming, good and "You must be crazy" :)

two state of the art outboards and the fiberglass work and rerig you would be putting around 40K + into it, that would buy a lot of fuel.

As much as I love outboards, not worth the hassle,sellit and buy a boat already set up with O/B.

Good points but....
 

consider that he'd have all of his old running hardware to re-sell to offset his investment.

As far as glass work, a couple of transom knees would probably be it besides glassing in the I/O holes. The knee's are fairly easy as you can do 90% of the fab work on your bench then just tab them in. Cardboard patterns and off you go.

Plugging the holes would be making a pattern, several layers of 3/4" ply, several layers of 1708 cloth and you're done. One side is hidden in the bilge and the other by the bracket too.
Bolt a bracket on and you're ready to rig.

IMO, the re-rig would be the most work.

He'd end up w/the same power at at least 1000lbs less and 50% more storage.
That conversion down here is huge and becoming more and more popular.

When my father was looking for a new fishing boat, he really liked one company and went shopping for one. He had 3 choices, 2 small I/O's, 1 big I/O or the O/B on a bracket. It's a 26' heavy glass boat but the O/B on a bracket was hands down the better boat in handling, fuel economy and had a few extra mph over the i/o's.....the biggest diference was the handling as the I/O's felt like the stern was dragging a parachute compared to the O/B - weight difference obviously. (boats were designed for I/O and the I/O's were factory propped)

Twin O/B's would have been much better arrangement but when this set-up gives him an issue we will put on an Armstrong bracket built for twin Verados. The O/B boat was ordered as such by a previous client that went cardiac and couldn't take delivery.....

For this boat it worked but the $$$$ involved was for a new boat on a even comparison Boat A vs. Boat B vs. Boat C so for a conversion you would have to see if the costs vs gain is worth it.

Resale is resale and you can never accurately define it (and the governement never offers any security for people to give up their money like they used too)

If it is an issue, spin what you have and get exactly what you want in a boat.

Using your assumed and un-calculated 1 mpg to 3 mpg ratio it sounds like it could be a worthwhile project.......but I bet you numbers are closer to 1.5 mpg now and 2.0-2.5 mpg with a pair of 300's. If I'm right (I think I am) then the numbers don't play out well.

Since you haven't calculated mpg, I bet you haven't done anything else to make your boat more fuel efficient. Make sure the motors are tuned and running their best. PROPS are the cheapest way to gain where you want to ....although you might sacrifice somewhere else. The props that were the fastest on my boat were rarely on it (5,650 rpms). I usually had a bigger set that still spun 5,200 but netted me a 5-7 mpg gain at 3,500. (Those 330's could be propped for about 4,500-4,600 if you just want to cruise)

BTW: My last boat, a 382, got nearly 1.3-1.5 mpg. I now have a 20 ft center console with a single Yamaha 150 4-stroke........gas mileage "only" jumped to 4.5.

I agree the glass work isn't the issue....it's the rigging.

The weight savings it great but the problem with all that additional storage space is stuff finds it's way in there.....permanently! Weight savings soon disappears.

Being you already run a twin O/B V-hull, what are your performance/fuel numbers for comparison? My post above highlights my OPINIONS, but not fact. Love to see some real world numbers.

I'm not knocking O/B's, I actually wish more boats were built this way. I'm just not yet convinced a conversion is the best way to get one.

I love the sound of those big blocks....To me thats what high performance boating is all about! But............. I went with outboards. For what I have in my boat (that has not hit the water yet) I could have easilly gotten a I/O boat. Around here the outboard guys are out every weekend. Pull up, flush & put it up for next weekend. The high hp boys are allways under the hatch and to me don't enjoy their boats as much.

With that being said.....If I were you I would wait for a outlaw with toasted motors and start from there. I think it would cost too much and not be worth it to do a conversion with a good running boat. Find a hull, buy a pair of mercury 300xs's and run up there in the 70's

How heavy is your boat? I hear many people say what you are saying, but, I've never seen real world data to substantiate the claims. There's no " replacement for displacement" an engine stressed uses more fuel to achieve the same speed- you have to push the throttles to stay where you want to be. A 2.5 liter outboard is going to burn more fuel pushing my 28' Pantera than a 6.2 liter SBC. Outboards have gotten better and bigger, hell you can now strap a V8 small block 350 Yamaha to the back of your boat, but I don’t think you save fuel. That said if anyone's got actual data showing something to the contrary I'd love to see it- I think we all would. Take the $$ for this project and throw it in a jar to buy gas.

My 22' deep v CC with a 225 optimax only gets 4mpg on a very good day. That's on offshore fishing trips staying at 3800-4000 rpms trying to save gas. I don't know what twin 300's on a 29' would do, but 3 mpg would be at the high end of the scale in my non professional experience.

It would be beneficial to all just to get an accurate estimate of the work and $$$ needed for such a conversion. The extra space would indeed be a great feature. While I have no idea of the work required and the $$$ needed, another more obvious setup would be to replace the current power with diesels. Given the OP's boat is a '99, you'd really have to keep this boat a long time to appreciate the $$$ invested. But I would imagine it's far, far cheaper than the alternative.

Another thing that comes to mind is the setup of new boats. While some brands have definitely delivered more and more OB-powered boats, they seem to assume everyone wants a CC. This might be due to the fact that it's the current In thing to build. But one of the reasons people like the CC's is space. Cockpit space to move around, and actual seats for people. Obviously, when you see 38' boats with bolsters and a few coffin chairs, the boat is setup for a single purpose. But you rarely see people enjoying themselves in the cockpit hanging out.

I see that Checkmate has a 280 OB, and Active Thunder has a 33 OB, which could be compared head-to-head against their stern-drive 33. Neither boat looks maximized for space with outboards, but the 33 is a very big boat compared to many.

Not many outboards in the used markets yet for this segment, and from the models available now, it looks like it will take another 10 years to get a good inventory.

Given you have twin 330's, it would be interesting to see what the experts would say regarding the weight issues. You'd have less total weight with the twin outboards, but they would be much further back. Does anyone know how this 29' hull would deal with those type of weight shifts?

Sell the OL and pickup a 33 PP o/b.

Concept makes a nice 30' sportdeck OB.

Powerboat test 78.4 mph - with 300s, plus enclosed head.

http://www.youtube.com/watch?v=9nAQJca_M44

28 Checkmate with twin Mercury 225 outboards. 70 mph and 3 mpg.

http://www.offshoreonly.com/classifi...o40299-en.html




http://i158.photobucket.com/albums/t...e/101B0140.jpg

also.....a buddy sold a 35 Cafe Racer with twin 540's and bought a 28 Boston Whaler CC with twin merc 225 (older carbed).......claims he gets the EXACT SAME mpg the Cafe Racer got, 1 mpg.

I like the comment about the 33' PP O/B's. I was actually thinking the same.
Theres one thats been for sale down here, forever w/twin XS's for I think $48K.

T500, I don't have accurate #'s on mine yet. Still tuning the motors and figuring out my fuel monitoring system. My best guess on my old 24' O/B w/stock versions of same power was about 2 MPG's @ cruise.
Remember too though, that's old school carbed motors and the new DI 2 strokes are between 40 - 50% more efficient. That would put me over 3 mpg's if my guesstimates are close.
BRP has a site to figure fuel savings on repowering w/their E-Tec's. At $3. per gallon I was saving $500. every 3rd tank based on their math. At $4. per gallon that savings goes to $650. per 3 tanks or $220. per tank @ 90 gals!

Is there a reason the pilot doesn't get a GPS display on that Checkmate?

I can't find the thread, but a guy in the islands put outboards on an Outerlimits.

I like the way the old o/b's sound. I think if i ever buy a cat i would get a twin o/b.

There's also a 42' Cig Tiger -
http://www.powerboatlistings.com/view/18053

Thanks everyone. Some good input here. I appreciate all the comments.

It takes a certain amount of fuel to make a certain amount of horse power.
Twin 300hp outboards are going to get about the same mpg as twin 330's. The weight difference may help some, so you might get 20% better mpg
It will cost 40k to do the rerig and if you're lucky, you might save $1000 in fuel per year.

Is there any definitive mpg #'s from the 39' Cig Top Gun open with trips compares to a Top Gun with a 525 package... I guess before I ask that, is the new TG open based on the 38 or 39 hull?

you would have to burn threw 10,000 gallons of gas just to break even if you could keep the motor's that long with out having repair's . that's if it cost $40k to install o/b.
that would also mean your going to go 25,000 to 30,000 mile's of travel with your boat , thats a lot of mile's if my math is correct to break even on cost .
Now if you motor's and drive are blown and you have to spend the same money on i/o's then I would consider the ob's

mike

I run a 34 Baja CC with 250xs's, best mileage I have seen is 2.2 MPG

Keep the BB's

I'm sorry that's the one I saw.