7M performance. I/O is better than OB?

zip · 31 May 2015, 22:24

I took a look at a brokered boat for sale today and the broker made the claim that the performance of your standard diesel I/O is far superior to an OB setup. He stated that this was because of where all the weight was located in your IO, and when you take a tight turn with an OB your stern tends to slide out from underneath you, or something like that.

I didn't want to debate this with him, since I have no clue, but I know that there are a fair number of people on this site that have the OB setup.

Xk59D · 31 May 2015, 23:00

https://m.youtube.com/watch?v=TL7xrE9EYd4

ncp · 31 May 2015, 23:02

1100 lbs of steel in center of the bilge makes for a smoother ride in the rough stuff. Also, having the engine under the console helps you plane quicker - weight forward. I go 0 to 20 knots faster than a friend with an H733 OTH with a 300 hp Yanmar back against the transom.

When think of "performance", I think speed. A Cummins turning 2600 rpm will never outpace a comparable outboard on the same hull.

Nos4r2 · 31 May 2015, 23:23

^ What he said.

There's not many (if any) inboard ribs the same size or smaller than my Ballistic with the 225 Opti that'd be faster on a flat calm day. However, there's a lot more to it than just out and out speed.

zip · 31 May 2015, 23:26

Xk59D, LOL!

Tom, That's interesting. I didn't know that. I told the broker that I am looking at two other 7M ribs right now, and one that I have been thinking about is an OB. I believe this broker may be primarily a sailboat guy, so maybe he just doesn't know?

On taking a tight turn at high speed, much difference?

RyanPratt · 01 June 2015, 00:53

turns will be almost the same, keep in mind when you make a turn in a IO you are generally going slower than an OB.

Willard 730 2x150 OB 38kn & I/O with Cummins 180 26kn. you can run a more steady pace in heavy heavy seas with all the weight of the I/O.

M2C

beamishken · 01 June 2015, 10:33

The debate between inboard or outboard could go on forever I think a lot is down to personal preference the two are different but which is best Is subjective
Best advice is go & sea trial both then decide
Also take into account maintenance is greater on an inboard

Bigtalljv · 01 June 2015, 14:37

And how do you plan to drive the boat? We are talking performance at the extreme end here. I haven't pushed my OB to the edge of turn capability and already I'd be worried about everyone (family) being able to hold on even if they know it's coming. It's a sports car/ rocket ship. If people were shooting at me I might think more about it.

The issue of IO vs OB in a heavy sea might be a valid though with the winds in CA but as a recreational user you probably aren't going out in that. As a commercial operator you could operate in that more. The OB will still get you home through anything.

My OB is very light and it will do low 20 mph comfortably through a central California small craft advisory. My wrecked back being the limiting factor and though it never really slams, it eases down into the next swell

Jason

Starovich · 01 June 2015, 15:16

No one has mentioned the elephant in the room. The inboard elephant that takes up all the space

Bigtalljv · 01 June 2015, 15:55

That's a whole different question....

zip · 02 June 2015, 13:42

I didn't know the maintenance on the diesel was higher. I have a diesel truck which has been limited maintenance, but it's not in a marine environment.

My primary use will be bopping around the bay, but mostly ocean travel to The Channel Islands. I will be sleeping on the boat. One reason I am looking at the Mil specs type of boat is if I get stuck over at an island in a small craft advisory, but need to get home at that time to get back to work. I have done that in my 4M before, and it wasn't sexy.

I am sure I will be happy with whichever I finally purchase.

For me, it comes down to money, time, mechanical ability(and space to work on boat), and availability.

If I had unlimited funds, I would by brand new with a single 4 stroke OB, or buy a used turn key from someone.
Next option would be to buy a semi project that might have a spent motor, or need new tubes, and pay someone to replace the motor. I could probably manage to mount a set of tubes.
Third option, which appears to be the most realistic, is buy one in working condition that might be a little rough around the edges.

I am considering making an offer on a boat I looked at last weekend, but we are pretty far off the $ amount. It is a broker, so I am not too worried about offending with a lower offer.

Thanks for everyone's input.

Andre · 02 June 2015, 13:52

As a matter of interest what is the average price in the US for a 7-750 rib with a diesel stern drive

zip · 02 June 2015, 14:21

Andre,

On the west coast of the U.S., for 7M Willard, Northport, and Zodiac Mil specs, I have over the last year seen them from 5k-50k.

ncp · 02 June 2015, 17:50

Quote:

Originally Posted by zip

Andre,

On the west coast of the U.S., for 7M Willard, Northport, and Zodiac Mil specs, I have over the last year seen them from 5k-50k.

In the used market.

New, they are $120k-140k.

Andre · 02 June 2015, 17:59

Quote:

Originally Posted by ncp

In the used market.

New, they are $120k-140k.

At those prices I am very suprised you guys don't look at UK or European manufactures especially for leisure use as the Jones's act will not permit for commercial. Even with a freight charge you will still get a better deal and a wider choice.

ncp · 02 June 2015, 19:34

Quote:

Originally Posted by Andre

At those prices I am very suprised you guys don't look at UK or European manufactures especially for leisure use as the Jones's act will not permit for commercial. Even with a freight charge you will still get a better deal and a wider choice.

A couple of people have thought about it. I know of a guy in San Diego that flew to the UK just to look at used ribs. Because he wanted a more leisure type rib (less workboat looking), there were many more options over there. I don't know if he ever bought.

In the used market, the $5,000 to $50,000 boats can range from very rough to almost pristine.

I've thought about getting tubes done over there. Lot's of options. New PU tubes for a 7.3m Willard from the mil-spec manufacturer, Wing, are $14,000 here. The only issue is getting a template to them.

Since there is more competition, I think that prices are more reasonable.

Andre, what's a base model, ~7m mil-spec diesel cost from Parker? (good quality engine/leg, but no extra seating/teak/top/arch/etc)

ncp · 02 June 2015, 19:48

Quote:

Originally Posted by zip

I didn't know the maintenance on the diesel was higher.

I don't know how much higher though. I do all of this myself as this engine is pretty straight forward (no electronics)

For my Cummins:
-New impeller, yearly, $65, 30 minutes
-Oil change, yearly (or at 75-100 hours), 14 quarts + filter, $75, 1-1.5 hours
-ATF for the transmission, every two years, $20, 20 minutes
-Gear oil, every two years (Konrad says up to 500 hours w/ synthetic), Royal Purple, per their spec, 7.5 quarts, $82.50, 1-1.5 hours (though I'll never find that price again, I'm working through a 5 gallon bucket bought for $220 shipped to my door)

Those are the basics on the Cummins. they say adjust valves at 1,000 hours Average yearly cost is less than $200. I would bet new twin outboards cost more.

Andre · 02 June 2015, 20:21

Quote:

Originally Posted by ncp

A couple of people have thought about it. I know of a guy in San Diego that flew to the UK just to look at used ribs. Because he wanted a more leisure type rib (less workboat looking), there were many more options over there. I don't know if he ever bought.

In the used market, the $5,000 to $50,000 boats can range from very rough to almost pristine.

I've thought about getting tubes done over there. Lot's of options. New PU tubes for a 7.3m Willard from the mil-spec manufacturer, Wing, are $14,000 here. The only issue is getting a template to them.

Since there is more competition, I think that prices are more reasonable.

Andre, what's a base model, ~7m mil-spec diesel cost from Parker? (good quality engine/leg, but no extra seating/teak/top/arch/etc)

OK will do it tomorrow cos must put some thought to it.
What you call mil spec is more what we would say commercial specification. Not to high jack a thread perhaps admin could slip this one.

ncp · 02 June 2015, 20:26

Quote:

Originally Posted by Andre

OK will do it tomorrow cos must put some thought to it.
What you call mil spec is more what we would say commercial specification. Not to high jack a thread perhaps admin could slip this one.

Ok, let's take "Parker" out of this.

If someone from the US wanted to order a commercial spec 7m from Europe, are they looking at saving $20,000/$40,000/$60,00 off the $120k-$140k list price of a Willard 7.3m?

(I've talked to Zip personally, I have a feeling he finds this interesting too)

zip · 02 June 2015, 20:55

Jason, have you ever changed the engine coolant, or the serpentine belt?