i/o questions

[the_anarchy16]

Hey all. I have a little tin can (14' with a 15hp) that im looking to upgrade. boat needs to be a jack of all trades so to speak. Still has to let me fish relatively easily, needs to be able to pull a wake board or tube, needs to be affordable to put gas in, needs to be trailerable and ok for small inland lakes as well as lake st clair and the Detroit river. Always believed in outboard power only but lately I have been reconsidering. Would like to pick something up this off season. Was thinking 18-21' range (most likely a bow rider to keep the wife happy, let me fish ok, and not be too bad for the kid on the way as he grows up a bit) cant afford a center console that's not trash. looking at late 80's early 90's. Would consider a cuddy as long as I could still get up on the bow and it wasn't too much of a pig (handling and fuel consumption)

1) Teach me about the extra maintenance an I/O requires
2) looking at everything, lots of 3.0L, 4.3L and 5L's available thoughs?
3) how much motor should I need? don't need it to be fast but it needs to be able to plane out and play with people in or behind the boat
4) what kind of fuel consumption can I expect
5) can these boats be run at WOT like an outboard or do I need to have some extra.
6) anything else you can tell me?

 

[agallant80]

Re: i/o questions

1) Teach me about the extra maintenance an I/O requires
You have bellows, and alighnment for the outdrive, also they are not self draining so you will have to winterize it.

2) looking at everything, lots of 3.0L, 4.3L and 5L's available thoughs?
Larger engine will use more fuel, Merc had some issues with the 3.0 I am sure someone will bring up those issues. I think its the 470?

3) how much motor should I need? don't need it to be fast but it needs to be able to plane out and play with people in or behind the boat
I would get the 4.3 good mix of fuel economy and power

4) what kind of fuel consumption can I expect
About 1.5-2 miles per gallon but depends on how you drive her.

5) can these boats be run at WOT like an outboard or do I need to have some extra.
No, You can run at WOT for a bit but you will ware out the motor if you do it all of the time. General rule is 75%

6) anything else you can tell me?
Im sure other will chime in with things that I missed or they don't agree with but now you have some things to think about.

 

[canyonken]

Re: i/o questions

What about a nice larger 20'+ Jon Boat with a 200 outboard on the back. I see some pretty nice metal cruising around the Mississippi that will do it all and clean up with a power washer.

 

[Chris1956]

Re: i/o questions

The I/O motor will weigh about 600# more than an outboard, making it harder to trailer. The I/O will use about 1/2 the fuel of a carb V6 Outboard of power comparable to the 4.3L I/O. Maintenance on the I/O will cost lots more than the OB. Maintenance costs will easily offset the cost of fuel, provided the OB is used "recreationally", not "professionally". The I/O woll take up lots more room in the boat than the OB.

Since you plan to trailer, I would pick the OB......

 

[the_anarchy16]

Re: i/o questions

Thanks guys. Why have I been hearing how much more reliable an I/o is? At half the fuel and half the purchase price they must be constantly breaking in ways that the average guy cant fix at home to offset the price? Room isn't an issue at that size, actually a doghouse is a good basking spot for the wife and opens up a full transom. As for towing. My Grand Cherokee can handly 7k no problem so staying under 21 feet I cant see weight being an issue either way.

 

[Mason78]

Re: i/o questions

If you plan on tubing/wakeboarding... I would avoid the 3.0L. In my opinion it does not have the power to get out of the hole quickly enough.

I cannot compare the maintenance to an outboard because I have never owned one. I have learned to do a good deal of the maintenance myself and have saved a boat load of money. There are youtube videos to walk you through nearly everything.

 

[QC]

Re: i/o questions

18' to 21' will get better than 3 MPG.

The 470 that agallant80 refers to is actually a 3.7 liter 4 cyl. Sometimes called a 170 or even a 485. All are the same issue. 3.0s are pretty bullet proof. They should not be confused, the only thing they have in common is 4 cyls. TOTALLY different animals.

Yes, I/Os clean up the transom. One of their major benefits. Also lower CG, so they do handle nicely despite the heavier weight.

Edit: to be clear, you do not want a 470!

Edit 2: moved to non-repair I/O

 

[the_anarchy16]

Re: i/o questions

Lower CG will most likely help on the big water around here. The more I read the more I'm thinking 4.3 alpha1 combo is the way to go.

 

[geneseo1911]

Re: i/o questions

Maintenance isn't bad at all if you're even a little mechanically inclined. For example, doing a transom seal job, which is needed about every 5 years, runs $400-$600 at the shop, but the parts are around $100. Winterizing runs $100-$300, but there is only about $10 worth of materials needed.

When you get into a bigger faster boat, I think you'll find you'll spend a lot less time at WOT, even if you like to go fast. Water conditions dictate speed, and even trying to run from one end of the lake to the other as fast as possible, I bet I can only run WOT about half the time. I wouldn't worry any more about running an i/o WOT than I would a 4 stroke o/b.

That said, even a 90's i/o is a likely candidate for rot. If the boat has been stored outside, I wouldn't buy it. If there are any cracks on the transom gelcoat, no go. Soft spots in the floor? RUN! You have to be VERY careful, as i/o's often leak a little and the owner thinks it's normal. O/B's are less likely to be rotted as they don't have a gaping hole in the middle of the transom. Of course fish finder transducers are the #1 culprit IMO, and all boats are candidates for that problem.

If I was doing it again today, ESPECIALLY if I was after a fish & ski like you, I would VERY STRONGLY consider an aluminum boat. I personally would be after a starcraft with a 4.3L Mercruiser. Almost as much power as a V8, a little lighter & shorter. I like i/o's because I find them easier to work on. I am very comfortable with automotive engines, but O/B's are a little trickier, again IMO.

My boat is a 19' FG bowrider with a 5.7L Mercruiser 260. I just finished replacing the transom. It is a little heavy, with a very deep V, and will run 50-52 MPH WOT. A full, long day of watersports will burn around 25 gal. Get the biggest engine you can find/afford. Fuel consumption is a function of the hull and the operation. If you don't use the horsepower, you don't burn the fuel. One caveat is that bigger engines are sometimes heavier. The 4.3L is in kind of a sweet spot for power vs. weight vs. size. 4.3L vs 5.0 doesn't gain as much as 5.0 vs. 5.7 for example.