IO v OB my I/O is Dead... opinons Please

G. Arruda

Petty Officer 3rd Class
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Jul 4, 2004
Messages
98
I'd love to get some guidance fron you OB guys, I think alot of what ail's my boat are I/O stuff...

Hx: My 1st pwr boat, 88 4winns OMC 3.0 17' IO trailered in NH. The boat is in great cosmetic shape. I've owned it 4 yrs, been well maintained by me and best guess the prior owner. BUT, lots of what I think are inherent IO issues are hitting the fan (and my wallet), Manifolds, LU seals, etc., these thing alone NBD, But the block is has an external crack for the last 2 seasons (tried expoxy, no luck) Anyway, leak isn't bad hasn't effected it's running (as long as the bilge pumps keep working)
So 2 ?'s: Do I throw in the towel on this one?

And what's the consensis on the ease of use and care of an OB v IO?
Are there makes and models to avoid???

Any guidence would be MUCH apperciated!
Thanks, Gary
 

Silvertip

Supreme Mariner
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Sep 22, 2003
Messages
28,771
Re: IO v OB my I/O is Dead... opinons Please

Check on the I/O - Mercruiser form for a post by me about how to create a plate to fix cracked 3.0 blocks. If the engine runs ok otherwise, do the repair and run it. I don't have time to try and find that post now but its a rather long one. Stay tuned -- Ill try to find it later and post the link.
 

Silvertip

Supreme Mariner
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Sep 22, 2003
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28,771
Re: IO v OB my I/O is Dead... opinons Please

Here's the text I provided in the I/O forum for fixing a cracked block. It obviously depends on where the crack is as to whether or not the fix can be used.

Here is a trick I've seen done, but it can only be done if the crack is in an area that is relatively flat. A slight curvature vertically or horizontally should not bother -- just not a compound curve. A flat steel or aluminum plate (3/16 thick) can be fashioned that covers an area about one inch above, below and to either side of the crack. Drill stop holes at either end of the crack to prevent its spread. Place the plate over the crack and if any slight forming is necessary, bend the plate as needed. Next, using a small drill bit to drill through the plate and the block. Repeat at the bottom. Next, drill the two holes in the plate so you have clearance for a cap screw. Fine thread, 1/4 inch should be fine. Now drill and tap the two holes in the block for whatever cap screw size you use. Now you can cut a gasket from thick gasket material, coat it with any number of sealers and bolt the plate in place. If you want to grind the crack and stuff it with the sealer it certainly wouldn't hurt. I've seen this done on a two engines in my life. One was a tractor that tossed a rod through the side of the block. The hole was big enough to stick my fist in. That plate had screws all the way around it and the owner never came back. My Dad did the repair. The second repair, also done by my Dad was done on a 6 cylinder Chevy. I might add that this was done back in the days when a buck was really worth something and things were repaired rather than replaced.
 

Bob_VT

Moderator & Unofficial iBoats Historian
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May 19, 2001
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26,065
Re: IO v OB my I/O is Dead... opinons Please

Drop me an email if this vanishes from the board but.... this was listed in a local give-a-way paper and it is in Rutland, VT it may help. If I had a need for this I would be jumping all over it.

Motorboat MFG Caprice 17', Mercury inboard/outboard. Tree fell on it in April storm

Gary send me a personal message - you have one.

Bob


We did have a storm of epic proportions in April.
 

G. Arruda

Petty Officer 3rd Class
Joined
Jul 4, 2004
Messages
98
Re: IO v OB my I/O is Dead... opinons Please

Cool idea for that block patch!
I'm still not sure if I putting good money for bad?
Thanks, Gary
 

studlymandingo

Commander
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Mar 22, 2006
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2,716
Re: IO v OB my I/O is Dead... opinons Please

I have owned both I/Os and OBs. I am now in the camp of sticking with an outboard. For me, it is much more versatile, handles the boat better, and much easier for maintenace.

I too like the Silvertip method for block patching; I would love to hear your results if you go this way.​
 

tashasdaddy

Honorary Moderator Emeritus
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Nov 11, 2005
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51,019
Re: IO v OB my I/O is Dead... opinons Please

i am part owner of an I/O chris craft. i lost the argument on this purchase with my sister. the only way i conceded in the purchase, is it was a really good deal, and had a volvo outdrive. i had one mercruiser, and do not want anymore I/O's. i'm and outboard man all the way. yes, you are hitting the I/O maintainance wooooos.
 

licketdsplit756

Petty Officer 1st Class
Joined
Jun 15, 2007
Messages
318
Re: IO v OB my I/O is Dead... opinons Please

myself i like the ob. due to the fact i can fish up till the first freeze...where as i have been told the inboards its not a good idea to run them when it starts getting really cold..i fish the ohio river and the walleye and sauger are aboundent around the locks in november early december.
 

Silvertip

Supreme Mariner
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Sep 22, 2003
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28,771
Re: IO v OB my I/O is Dead... opinons Please

One thing I failed to mention is that if the crack is fairly long one might need to make the plate a diamond shape and add screw(s) at either side. If someone would take a picture of an engine with a cracked block and send it to me via private message I would be happy to illustrate how to create the plate. One must be aware that this only works on cracks on the outside of the block. If there are internal cracks as well you are definitely in the market for a new block.
 

hkeiner

Lieutenant Junior Grade
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Oct 17, 2006
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1,055
Re: IO v OB my I/O is Dead... opinons Please

I chose an OB over an I/O for the primary reason that maintenance and repairs could be more easily handled by me with an OB. I don't like to pay others to do my maintenance and repairs if I can avoid it. I believe that I/Os have more complicated (expensive) repairs that OBs. A second reason is that they are lighter for towing purposes.

However, I do think that I/O are generally nicer boats to drive.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,313
Re: IO v OB my I/O is Dead... opinons Please

Started with I/O and changed to OB after 5 years and will never own another I/O. I boat 10 months out of the year and draining the block between useage isn't cutting it. Either was replacing the gimbal bearing every other year.

The OB gives me the same HP at 1/3 of the weight and is easier to work on to boot.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: IO v OB my I/O is Dead... opinons Please

In my opinion the only advantage to an I/O is brute horsepower that dollar for dollar is fairly reasonable. I don't think the automotive type motor is happy
in the marine application;especially if run a lot at its max rpm rating.
Not sure why but it seems there is a high persentage of I/Os on the prop forum.
 

G. Arruda

Petty Officer 3rd Class
Joined
Jul 4, 2004
Messages
98
Re: IO v OB my I/O is Dead... opinons Please

Thanks Guy's!
Pretty much the thought process I have.
Now... anything to avoid???
I can't afford new yet (6more yrs of college tution)
Thanks again, Gary
 

scoutabout

Lieutenant Commander
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Oct 14, 2006
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1,568
Re: IO v OB my I/O is Dead... opinons Please

Sounds like you've got a lot of good feedback so mine will just be futher confirmation. Our family started with outboards in the sixties and we owned Scott, Evinrude, Johnson into the seventies. The eighties became for us the Age of Mercury in a relatively serious way with two 7.5s (one a long shaft electric pushing dad's sailboat, and the other a shortshaft that I still have on a 14 foot aluminum), a 40 Merc 2 stroke on a 15 foot runabout, then a repower to a 70 Merc 2 stroke.

This was in the time of the smoky blue haze following you everywhere you go, mixing gas and oil or buying outrageously priced (oh, for those outrageous prices now!) premix at the marinas. Our attitude wasn't helped by the fact that the 70 overheated and failed in the first season due to a faulty impeller installation at the factory and never really ran well after the rebuild.

So in the mid-nineties we decided to try I/Os and ran a SeaRay 170 with the little 3 litre Merc for ten years. I loved that boat and logged some serious hours, and at first the "out of site, out of mind" motor was a nice novelty. With the sunpad there was a whole new area of the boat to use. And no endless flipping the ski rope around the outboard. And with that little Mercruiser on a smallish boat fuel economy also picked up considerably.

However...as others have stated, when you do your own maintenance, it starts to get old fast contorting yourself around the motor block, outside in early November freezing drizzle to find those manifold drains. Or sucking oil out of dipstick tubes, or trying to reach hydraulics crammed way in the back, or worrying about outdrive alignment, torquing gimbal bearings, and on and on. And frankly knowing that there was only a thin rubber driveshaft bellows (under constant assault from the elements) between me and the bottom of the lake always gave me the creeps.

Fast forward to the age of the clean-running 4 stroke outboards and we decided to make the switch again last year. It's only been half a season, but I am really enjoying having everything totally accessible in one neat power package hanging off the back. That motor-mounted tilt switch is heaven too (although, granted I have seen some I/Os retrofitted with them). And if I have to repower in 500 hours or do some serious recon work, there is eactly one wiring harness, three bolts, and a fuel line between me and the workbench. Or, thinking about it another way, it's far, far easier taking an outboard with you to your next boat, should that come to pass.

Yes, the four strokes come with their own hassles such as timing belts and this mysterious "making oil" thing, but frankly getting at the belt on that motor is far easier than the one in my car and so far, I've not seen anything amiss at the dipstick.

And, the damn thing is just so fine lookin' sometimes I let others drive so I can just sit, facing backwards watching it work. *cue wife's rolling eyes and head shaking*

I know many of my richer friends who just toss the keys and a thousand bucks at the marina every fall and thus have so maintenance issues themselves wouldn't necessarily agree with my assessment, but then maybe I wouldn't either under those circumstances.

But for the way we approach boating I'm gonna say -- come on in, the water's fine!
 

G. Arruda

Petty Officer 3rd Class
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Jul 4, 2004
Messages
98
Re: IO v OB my I/O is Dead... opinons Please

Excellent thoughts, Thanks!
 

hitace

Petty Officer 1st Class
Joined
May 4, 2007
Messages
390
Re: IO v OB my I/O is Dead... opinons Please

every thing about a outboard is much simpler and easyer.and hay if you ever need a new one unscrew 4 bolts and pop on a new one.with a i/o your pretty much stuck with the same HP forever :(
 

TriadSteeler

Petty Officer 1st Class
Joined
Oct 26, 2006
Messages
237
Re: IO v OB my I/O is Dead... opinons Please

No matter what you do to it, an automobile engine is just not designed to work in a marine environment the way an outboard motor is.

I just revived a 33 year old and 10 year dormant outboard for about $120 (carb kit, fuel hoses, new LU lube & some new wires) which fired up immediately with a little choke.

Try that with an I/O that has been sitting for 3 years let alone 10. I don't care how ugly that OB looks on the back or what concessions I have to make as far as a swim platform, I'll always have an OB.

The only exception would be a boat large enough to where I had to have an inboard diesel.
 

hibbert6

Petty Officer 1st Class
Joined
Jul 15, 2006
Messages
323
Re: IO v OB my I/O is Dead... opinons Please

OK - So how do you crack the block on a lake-water cooled engine??? And if a lot of people are having this problem, it sounds like a class action suit waiting to happen!

(No, I'm not a lawyer!)

Dave
 

jtm71

Cadet
Joined
Jun 26, 2007
Messages
6
Re: IO v OB my I/O is Dead... opinons Please

I have owned both I/Os and OBs. I am now in the camp of sticking with an outboard. For me, it is much more versatile, handles the boat better, and much easier for maintenace.

I too like the Silvertip method for block patching; I would love to hear your results if you go this way.​
I agree!! Less work! Better fuel eco!
 

njlarry

Petty Officer 1st Class
Joined
Sep 13, 2005
Messages
330
Re: IO v OB my I/O is Dead... opinons Please

If I may present a dissenting opion;
I find IOs easier to work on. They are familiar auto engines. They do not have complicated electronics. How do you guys test all the sensors and computers on OBs? Ios are quiet, start easily, reliabile, burn less gas, and have WAY less cooling issues (why do OBs have little cooling passegages combined with no temp gauges-these forums are full of sudden catastraphic OB melt downs). The only advantage I see with OBs is that you can work on them standing up.
The weak link with IOs is the outdrive unit and I wish manufactures would come up with better @##% gimbel bearings.
my humble 2c.
 
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