Mercruiser I/O vs Outboard SeaCraft?
 

I have found a 1970 20' cc for sale and it has a 140hp mercruiser on it. I would be using it in a bay for fishing and skiing. I have no experience with boats/motors. Am I asking for trouble? Just wondering if an i/o would be more of a problem for a first time boat owner or should I search for something with an outboard. I don't know any different? Would I be able to put an outboard on in the future if I had problems with the i/o? What are the advantages/disadvantages? Thanks for any help.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

If you're ready to get very involved with the life of your motor, the i/o will be fine. I run one and used to run outboard and the i/o definitely requires a different degree of vigialance and maintenance skill for you to be a happy boater.
If you don't like getting your hands dirty, stay away from the i/o.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

Amen, brother

Re: Mercruiser I/O vs Outboard SeaCraft?
 

IO's that are used in salt versus fresh that sit for
extended periods do tend to be more labor intensive.
As for outboards they can withstand neglect a little
better... IMO
Variables also to consider is if you are in the frozen north or the balmy south.

If the price is right, well just go for it. :D

See ya, Ken

Re: Mercruiser I/O vs Outboard SeaCraft?
 

IO would also be alot easier and neater to do a transom enclosure in the future.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

I'm in north carolina and the boat would be trailered and not kept in the water, but I would be using it in saltwater. So what would you guys suggest knowing this? When you say an i/o would be easier to enclose in the future, do you mean it is possible to replace the i/o with an outboard if I chose to?

Re: Mercruiser I/O vs Outboard SeaCraft?
 

To put a full transom and a bracket. I am rehabing a Sceptre and if I started over today I would enclose the transom and put on a bracket or a "jack plate".

Re: Mercruiser I/O vs Outboard SeaCraft?
 

I/O's do require more maintenance. But if you are not handy, a good local mechanic should be able to keep you up and running no problem.

With that said, a brand new 140hp Outboard is around what $8-10k these days. A brand new 135hp 4 cylinder Mercruiser package (engine, transom assembly and drive) is $5995. Plus, because so many boats were made with the 4 cylinder Mercruiser engines....there are a ton of parts and slightly used motors available.

I would not necessarily be afraid of an i/o. Just know what you are getting into.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

New Mercruiser 135 sterndrive package - complete less controls & cables, prop, gauges, etc. = $5,906
New Mercury 135 Optimax - complete less controls & cables, prop, gauges, etc. = $9699

According to an article I read in Trailer Boating magazine about 4-5 years ago, which was based upon a 2002 study by the E.P.A. on the impact of marine engines on the environment:
Average life of a well maintained sterndrive - 2,250 hours
Average life of a well maintained 2 stroke outboard - 1,500 hours

And according to 2004 study by the University of Wyoming, assuming a usage of 100 hours per year:
Average maintenance hours per year, sterndrive = 21
Average maintenance hours per year, 2 stroke outboard = 14
Average maintenance hours per year, 4 stroke outboard = 18

FWIW

Re: Mercruiser I/O vs Outboard SeaCraft?
 

To follow Fr. Frank's post, if you do most of those maintenance hours on the stern drive when you are supposed to you will generally be a happy boater. Guys get themselves into trouble-big trouble sometimes-when they don't perform the big ticket maintenance items. There are a few-the drive bellows, in particular, that require your frequent inspection. I have been very happy with the package-my mercruiser has been very happy for the last three years and as Fr. Frank stated if the ill-fated repower day comes at a bad time-I'm looking at about 6000 for a brand new drop in 250 hp mercruiser engine to replace mine.
Good luck with the choice and feel free to pm me with any specific questions. :D

Re: Mercruiser I/O vs Outboard SeaCraft?
 

And there are some deals to be found on sterndrives.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

If you're trailering it and not leaving her in the water - then the I/O is a nice choice. Think about whether you're in shallow water a lot. An O/B is nice to have in that case...

At this point, most people can't work on these 4 stroke O/B's much anyway - they're pretty technical in terms of Fuel Injection etc ( I've heard this from some of my very mechanically inclined friends )- as are the i/o's w/ regard to Fuel Injection and sensors. The I/O, if taken care of - think PREVENTATIVE MAINTENANCE! should be pretty straight-up. And, I feel they perform better than an O/B in terms of response.

I do all my own winterization and summerization and anything I can. It's fairly simple. One thing I would like to get my hands on is a Mercruiser Maintenance schedule. The Mercruiser service manuals are pricey - $150 for engine and $150 for drive manuals.

I have a MAG 350 Mercruiser 5.7 w/ a Bravo 3 on my 23 Tsunami. It is an awesome setup. I get about 8-10 gallons per hour at 3100 rpm's. WOT is 4400 rpm's. I would have no complaints if I trailered her. The fact that I keep her in the water comes with (1) concern, (1) design flaw and (1) maintenance PITA:

In order:

- electrolysis / galvanic corrosion - is a real fear/ concern. So far so good, but I am on it. As the song says, "Rust Never Sleeps "

- distributor cap contacts ( inside the cap ) constantly gets fouled from moisture. Mercruiser recently switched back to copper/brass ( I forget which ) contacts from aluminum <--- alum was atrocious !

- and by far the worst - the marine growth ! I have to clean my drive, underwater, while in the water, 2-3 times a year - 2 hours each time. The growth is insane.

For me, when I did my resto 5 years ago, I thought about the O/B's, but the add'l price and benefits were not enough to make me do the extra work.


Hope this helps a bit.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

Ab...I have a 350MAG Horizon B-I in a WAC...it's a nice package, good power and >2.5mpg. It's a 2006 and the WOT range on it is 5800-5200....which seems insanely high for a
small block V8. I think earlier years had a range of 5600-5000. At 5400 WOT you seem a little overpropped???

Re: Mercruiser I/O vs Outboard SeaCraft?
 

Oops....that should be 4800-5200 WOT range
and 4600-5000 on the earlier years (pre-2006).

Re: Mercruiser I/O vs Outboard SeaCraft?
 

My last boat was an I/O and we switched back to an outboard primarily for the easier maintenance and greater interior space. It's not that the maintenance on the I/O is difficult. It's probably the most common engine in the world and consequently there's no shortage of people to give you advice or to work on them.

The problem is that when shoehorned in to the boat everything is hard to get to. You need to be a contortionist to change the spark plugs. Changing the oil filter with out spilling in to the bilge was enough of a problem that we installed a remote filter. I was also never comfortable sucking the oil up through the dip stick. Changing the starter called for a saw and a lot of bloody knuckles. With the outboard, everything is right in front of you at eye level.

All that said, I do still miss the performance. You had a better weight distribution and as much hp as you could ever want and all with the quiet operation of 4 stroke and a fraction of the cost of an OB.

Bottom line, I wouldn't shy away from the I/O, especially for a trailer boat. If its going to be professionally maintained I might even prefer it. If you're worried about getting in to the shallow water, sure an OB is better but a trolling motor is even better still.

If you do get it, heed the advice given here and keep an eye on the bellows.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

One other thing I like about my i/o-something other people complain about, actually, is the engine compartment serves as a great casting platform in the stern. My buddy and I do a lot of casting and we both have our own region of the boat to work from-lot's of fun.
That mpi listed above must really improve performance over the carb-I'm not close to that speed with my 23 cc. I top aout at about 40mph. I suppose if I bucked up and removed the bottom paint I may pick up a few mph, but it's jsut such a nasty job that I don't want to tackle.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

anotherr benefit to the I/O is the improved transom access. Doesn't matter if it's for fishing, swimming or waterskiing. They get in the way less than an outboard and in my opinion look nicer too.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

I'm in the process of doing over a 74 Tsunami,with I/O power,and hope to have it in the water sometime this coming season.
I thought about a bracket with an outboard,but after i did the math,it was realistically a lot more than i wanted or could afford to spend.

I always was an outboard guy,but around twenty years ago i started fishing the great lakes,where I/O's or straight inboards seem to be the most popular choice of power.
I own a couple I/O boats,and am very happy with them.Both mid eighties drives,one Cobra,and one Mercruiser.

I/O's and Outboards each have pros and cons.Everyone always talks about more deck space in an outboard powered boat,which is true,but for us,trolling with as many as eight rods off the sides and stern,a big outboard hanging off the back makes it very difficult to net a big salmon.
I love that big high flat wide transom,even more so when it's nasty,and the waves are following me when I'm trolling,and
yes,the motor hump can get in the way,but it is a good place to also do some rigging of lines.

As for maintenance,you do have things like the bellows,and shift cable boots that need inspection and occasional replacement to keep the water where it belongs,on the outside of the boat.
The drive has more parts,(gears,u-joints etc)to wear,so in that sense a good maintenance schedule pays big dividends.
One of the pluses,(to me anyway), is that if you go with a carbed powerplant,it's basically a car engine,so you can do lots of repairs yourself,however,plan on getting yourself a pair of knee pads,because you'll be on them when you're working on it.

I happened to get a chance to look under the cowl of a new big Yamaha four stroke "EEK awesome,but very scary,not much there i could fix.
Did i just read on this site that the 350hp Yamaha otbd.was around $24,000.00? A new 300 hp 350mag complete with the drive is about half that.

The fact that you can't tilt an outdrive completely out of the water can be a disadvantage for you salt water folks as far as corrosion goes.
If you fish late in the season,when the temps can be freezing, the I/O can be a disadvantage,as it would have to be winterized with antifreeze,after each use unlike an outboard that drains itself.

I wouldn't hesitate to buy a boat with an I/O, but you say the boat is a 1970.Is the outdrive the same year?Some of these older drives had big rubber seals that were prone to leaks,and gear driven tilt and trim mechanisms that could be problematic.

If it's an old drive,I'd give some thought to replacing it with a later model.There's lots of used ones around.If you're replacing the transom,and need a mercruiser cutout pattern for the drive hole,i have one from mercruiser that i can give you.

Finally,my apologies to all the previous replies, if i repeated your answers,it wasn't intentional.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

I've got a couple of pictures of the mercruiser, but I don't know how to post them?

Re: Mercruiser I/O vs Outboard SeaCraft?
 

what is the ballpark selling price on the 1970 i/o that you are looking at. is it a good deal. good floor etc.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

$5,000 is what he's asking. I don't know if that's a good deal or not? I'm a 1st time buyer, that's why i'm so nervous about buying an older boat like this. Floor seems fine, but looks to need a paint job, spider web cracks in the paint.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

testing to post pics? spider cracks in paint, transom, motor
[image]http://i257.photobucket.com/albums/h...r/P1010014.jpg[/image] [image]http://i257.photobucket.com/albums/h...r/P1010024.jpg[/image] [image]http://i257.photobucket.com/albums/h...r/P1010017.jpg[/image]

Re: Mercruiser I/O vs Outboard SeaCraft?
 

There's a couple things i see that i are not right. ask the seller what in the world is a deck plate doing on the outside of the transom?.Did you unscrew it and check inside?See if you can feel the wood core.

The aluminum plate where the outdrive bolts to is not normal,and is there for one of two reasons.#1 is that the transom core is bad,or #2 it's some kind of adapter plate to fit with that outdrive,although the outdrive in the picture(at least the upper part)is an early 70's to early 80's model,so it shouldn't need that aluminum plate.

Mabe I'm wrong,but I think the price is high for this boat,and from the picture you posted,I'm thinking that once you start digging,you're going to find lots of areas that need replacement.
I'm sure some other guys will chime in to give their advice.

You may want to keep looking,there are other seacrafts around,and prices now in this economy are pretty good.There was a nice 20'scepter that sold for $6,000.00 near me a couple of months ago,and it was in good condition.They are around,you just have to keep looking,and be patient.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

Wow! I second that . That is definitely 2 red flags! Not normal!

Re: Mercruiser I/O vs Outboard SeaCraft?
 

The cracking in the fiberglass you see is more than normal crazing, and indicative of excessive stress. The deck plate of the left of the transom goup is a sunk boat waiting to happen. The gimbal housing is newer style, but the drive itself loks to be original pre-Alpha. The aluminum plate around the transom group would cause me to avoid this boat without figuring on absolutely replacing the transom core.

Re: Mercruiser I/O vs Outboard SeaCraft?
 

Seariously, I've been lurking for a while...reading a whole lot of the acrhives...I was feeling so inspired I bought a 74 20 savage (outboard).

When I saw the pic above with the pie plate thru the transom !!!! below the waterline!!!! it was motivation enough for me to regester...

That's a classic, are they kidding????

This was well worth spending my first post on!!!!

Re: Mercruiser I/O vs Outboard SeaCraft?
 

I could be wrong but the pyhi/deck plate has to do with the livewell? :D

Re: Mercruiser I/O vs Outboard SeaCraft?
 

Your not wrong Don..
My 20 has the plate in the same place.
I put a strainer plate on the outside and a sealed one
on the inside of the live well. The original was drilled
holes through the glass skin. It looked hokie with the holes, hence the 4 inch strainer plate.

See ya, Ken
http://i7.photobucket.com/albums/y27...PDR_0011-1.jpg