Benefits of the I/O engine?

Hi, I am building a 24' boat and I was wondering what the benefits of a I/O over the outboard. I have heard that they are more efficient and reliable, but I have also heard that this is changing. Obviously size is a drawback. Anything else?<br /><br />Thanks<br />mike

Re: Benefits of the I/O engine?

Try a search on this topic....it has been discussed heavily in the past. You will learn the benefits and draw-backs.

Re: Benefits of the I/O engine?

Well the most obvious is that it is based on a simpler and cheaper car engine (usually GM V8 or V6)which is easier for some shadetree mechs who learned on cars first. BUT then there is the outdrive, which can be troublesome, needs a lot more maintenance than an outboard esp when used in salt water. An outboard can be tilted up out of the water, the outdrive is always in it, so you have to be meticulous about painting it and using anti fouling on it. So on the balance initially the I/O may be cheaper to buy, but more expensive to maintain, esp if you can't do it yourself.

Re: Benefits of the I/O engine?

novice,<br /><br />I deleted your other post that asked the same question. Since that one did not have any responses, I decided to leave this one.

Re: Benefits of the I/O engine?

Novice<br />The I/O is a four cycle engine so it is quieter and get better fuel mileage than a same HP carberated 2 stroke outboard. Also since it does not burn oil in the gas runs a little cleaner. Today the direct injections 2 strokes get very close to the same fuel maleage and also run very clean. The 4 stroke I/O or outboard still does not burn oil so still a little cleaner. The wieght of the I/O is heavier and also farther foward and lower so I feel help's hold the bow down to cut waves better. With more weight lower boat rolls less in big swells. The outboard is lighter and farther back. Same HP 2 stroke should be a little faster, 4 stroke outboard also since still lighter than the I/O. Lower units on both the same basic units. The I/O will have a extra gear box to change the direction of your drive shaft. The engine part of the I/O is eaiser to work on and requires fewer special tool. If you have done you own car work will be almost the same. Many say the I/O takes a lot more room but I do not find it to make that big a difference. True the motor is in the boat and takes up room but most Outboards have a motor well that also takes up room. Motor cover makes a nice place for the Ladies to lay out when fishing is slow. If have a fuel leak on a I/O, fuel and fumes end up in bottom of boat, the outboard goes in the water. Maintenance of the I/O is more as have the extra gear box and if run in saltwater exhaust manifolds fail in 4 to 6 years.<br /><br />Still I prefer an I/O with a outboard kicker motor. One thing I like is if should fail while out in the ocean I can start up the kicker and put the wife at the helm and have her start in while I take a look at the motor. On a outboard your not really going to work on at sea, most would probably do is change plugs.<br /><br />This did happen to us one day. Turned out to be a operator error I think. We were about 12 miles off shore fishing and near our normal time to go in when we spotted about 5 whales a little further out. We went out as close as felt safe and shut engine down took some pictures and then wanted to go in but engine would not turn over at all. Wife got scared but started kicker motor gave her a compass heading. Opened up motor checked for gas fumes then jumped started solenoid with a screwdriver. Motor started right up. After got back to the dock shut motor off and started many times. Never did get to fail again. I think when I shut it off while watching the whales did not get it into netural. Had this been an outboard I do not think would have worked on till back to the dock as that day had about a 6 foot swells.<br /><br />Today I think it is more personal preference than anything else. The Fuel injected outboards are just as good as the I/Os today. They require less maintenance and should you decide to get bigger motor or replace a tore up one much easier.

Re: Benefits of the I/O engine?

Thanks for all the advice! I am sort of a back yard mechanic and have done my share of engine rebuilds as a hobby. I have an outboard on my other boat and it is finicky as hell and burns all sorts of gas. I'm goin I/O and I'll be sure to keep up on the stern drive maint.<br /><br />mike

Re: Benefits of the I/O engine?

My personal preference is definately for an I/O. A finely tuned V-8 with a merc./volvo/cobra drive is hard to beat for dependability, performance and economy in a 24' boat. My brother has an older 16' Campion with a 70' Johnson on it and it burns nearly twice as much fuel as my 22.5 Sea Ray does (305 merc.). Plus we cruise at the same speed. One vote for I/O from me.<br />

Re: Benefits of the I/O engine?

I suggest that the benifits of one type of engine vs another has alot to do with the size and type of boat. Outboards have come along way in just the past few years with fuel injection and 4 cycle and I'd say they are the best for smaller boats, lets say up to 21 feet, hands down. After that the horsepower requirements approach or exceed 200HP. That translates into a big outboard(s) and HEAVY and expensive, especially a 4 cycle. Having all that weight hang off your transom can cause problems. Just fitting an IO in a smaller boat creates a motor bulge in the floor. The larger boats have the room below deck to accomadate the motor, its quieter and when compared to a 2cyl carburated OB much more fuel efficient.<br /><br />My opinion up to 21 feet, a 4 cycle outboard (When you talk a carburated 2 cycle outboard, the IO makes some sense after 19 feet, for shopping used boats), 22 to 26 single I/O, 27 to 30 twin IO, v drive or screws, 30 up twin screws. <br /><br />The middle sizes 22 to 25 can have wiggle room. On the plus side an outboard is raised all the way out of the water, so if your keeping it docked, maybe get an outboard for the larger boat. But if you are mechanically inclined, get the IO, you work on the motor and have an expert work on the drive and maintain it.<br /><br />Just a rule of thumb from a person with a little knowledge (as they same a dangerous thing).

Re: Benefits of the I/O engine?

Had you posted this on the outboard section of this forum, you'd be receiving a whole bunch of "the outboard is better." <br /><br />Sounds to me like you already had your mind made up and decided to get affirmation on the I/O section.....

Re: Benefits of the I/O engine?

I've had both I/O and outboards on boats 20 feet or under and have enjoyed all. Much depends on the type of boat, it's primary use and the body of water it may be used in. For instance, my current rig is a closed cooling system I/O which is well suited to fresh as well as salt water.<br /><br />The benefits of an outboard on a 20-or-less foot boat should be considered. The additional space available in the stern and the opportunity to easily up-grade or re-place a power plant are serious considerations. Having owned both, I know it's a tough decision. Right now, since my boat stays in the water for the duration of the season, and a well qualified mechanic is one mile away, I'm enjoying the I/O.

Re: Benefits of the I/O engine?

Then there is money. Some 4 stroke out board these days cost as much as my first house! You can build a bad a$$ V-8 for under a grand. Most used outdrives (in good shape) run about a grand new for $2500.00. Still a lot cheaper then a 4 stroke.