Ideas please? Engine/drive replacemet in boat.

supernova2, Jan 24, 8:28am
I really know nothing about boats but I don't think spending $6K on a 21 year old motor sounds like a good idea.Whats the parts supply like for boat motors that old!

From what I've heard most boat motors tend to die from neglect rather than wearout.

As long as you have an appropraite transom in your boat then fitting the engine is dead easy is it not!

Surely for $6g you could pick up a newer motor.

skin1235, Jan 24, 9:46am
would it not change the balance of the boat by hanging that 150 out the back
I'd suspect you would need to modify or fit bigger cavitation plates and possibly decent dolphins to the outboard
will you be able to modify the current steerage or will you need a full system to suit the outboard,
same for the throttle and gear change, assume the stern leg has electric lift and this should be a simple wire in a short extension to the outboards lift
just how bad is the leg you've got!
why not repower or replace with same or repair the engine already in the hull, it will be easier to balance etc

thejazzpianoma, Jan 24, 10:01am
I seem to remember some fairly stroppy V6 marine diesel inboards on here a while back (new) that I thought were pretty affordable. That's what I would be chucking in.

sr2, Jan 24, 10:43am
As much as I love the old Black Max Merc??

rob_man, Jan 24, 6:50pm
I like the look of the Volvo in sr2's link, appears to be a Ford motor. The main thing is its completeness, everything from key to prop.

pdc1, Jan 24, 8:52pm
definitely not that old merc outboard. Need to tell us all details, exactly the boat, condition, intended use, and who is doing the conversion.
The balance issue that has been talked about may not be a problem.
If you are going to do the conversion, get a later model engine, preferably a 4 stroke (although the weight factor gets worse), otherwise you are taking a step backwards to the engine you have already got.
What do you mean that the engine is not working! Is it just the leg or engine too! These were a great engine. Maybe you can fix or replace just your leg! There is a great danger here in the proposed conversion that you never get your money back. At least with a new(er) engine, especially if 4 stroke, it becomes a selling point.

sr2, Jan 24, 9:12pm
I would be very surprised if the ???balance issue??? wasn??

elect70, Jan 25, 2:50am
Depends on cost of fixing the mercruiser -can you get partsreasonable $I heard they werevery expensive .Probably better to put in anotherstern driveMate has a 20 ft glass over plycabin cruiser with 200johnson, but can see it origonally had an inboard , its agas gobblinguselesspigpaid 20 G$ for itmug

pdc1, Jan 25, 5:34am
yes definitely something that needs calculating as it does change as you say, but my words were "may not".(be a problem) a rough guess, a lightweight outboard maybe close to half the weight.Just trying to say that the project shouldn't be shelved because he read on the forum that it won't work. It just needs considering and calculating by someone who knows.
Remember the original engine is probably rated at flywheel horsepower and the newer outboard will likely be hp at the propellor, so maybe some weight savings from a smaller outboard is possible.
It's also why I made the comment that we need to know all the details, as the cabin design and construction will be a big consideration in the balance issues.

snork28, Jan 25, 5:46am
i would go for something like this Listing #: 553891367

daryl14, Jan 25, 6:53am
Agree with above, go for volvo or yanmar (marinised toyota) turbo diesel.

Other option is get a crate LS1 chevrolet then you get an EFI V8 which should bolt right in.

grangies, Jan 25, 7:08am
Cheers.

Looks the way to go.

It will be a mint old boat once we finish it, will owe me about $12,000 with a good refurbished tandem axle trailer, and a decent engineand stern leg like the Volvo in the links above.

It would go like the clappers, with that Volvo V8 5.0FL.

thejazzpianoma, Jan 25, 7:19am
I agree, replacement inboard makes a lot of sense, do bare in mind though that the cost difference between running a petrol and diesel inboard is monumental. Aside from the efficiency there is no unnecessary tax to pay or mucking about trying to claim it back either.

People wake board and ski behind Diesels so its not like it has to be some old under powered plodder either.

grangies, Jan 25, 7:37am
I know what you mean. The only problem for me is the $$$ cost of a reasonably late model diesel engine, compared to it's kw output.

yudasgoat2000, Jan 25, 9:16am
How much are the Hyundai Marine engines!

ralphdog1, Jan 26, 7:09pm
How would the weight of the Iveco compare with the Merc 165 that is installed at the moment!

NZTools, Jan 26, 7:29pm
It will be quite a bit heavier, but it will go like a raped ape.

thejazzpianoma, Jan 26, 8:07pm
Being an Iveco that would be a metric ape too, so even more impressive.

thejazzpianoma, Jan 26, 8:41pm
As an educated guess I would expect it will be around 550 - 600KG, so look at it as weighing the same as two 350 Chev V8's.

I am just talking about the bare engine not the Jet unit and again it is an educated guess.

Realistically, for your size of boat as much fun as it sounds in principle it is probably getting carried away. Probably only cost about $30 an hour to run going at some absurd speed though which is impressive for 270hp!

Hope that helps put it into perspective, please check my estimate before relying on it to make any sort of decisions though.

flack88, Jan 26, 9:12pm
That diesel would safer as well,i can remember alot of inboard petrols going up in flames back in the day.Be ALOT cheeper to run than benzine,if it runs ok it be good for years,know peoplethat spend up to 5oo or more a day,on fuel for the big outboards!