TSUNAMI I/O repower
 

Just got a 1973 tsunami with original 188 merc I/o Want to repower I am considering a 5.0L 220 HP merc alpha any info on speed fule consumption or insilation would be helpful thanks

Re: TSUNAMI I/O repower
 

Chris welcome to CS... This was the speed thread here: http://www.classicseacraft.com/cgi-b...c;f=1;t=000292 hope that helps you ...

That's the boat from MV Marine Brokerage, right? I twice e-mailed that guy on the boat you bought and never heard back from him and he missed me on a 20 hull just after they blew it up (not his fault on that one)... Again welcome to the site - any pics on that boat? Wondering about the woulda, shoulda, coulda... BTW - that'll be a sweet Derby Boat [img]images/icons/grin.gif[/img]

Re: TSUNAMI I/O repower
 

Is that Tsunami a 20' or a 23'?

Re: TSUNAMI I/O repower
 

JOHN R I DO NOT THINK THIS BOAT WAS LISTRD WITH MV BROKERAGE I GOT IT FROM A GUY IN GAY HEAD THE HULL HAS BEEN PAINTED AND LOOKS A LITTLE BRAT UP BUT EVERTHING IS SOUND CANT WAIT TO TRY IT OUT THANKS I HOPE THIS GETS POSTED BECAUSE I HAVE NEVER DONE THIS

Re: TSUNAMI I/O repower
 

ITS A 23

Re: TSUNAMI I/O repower
 

No prob Chris - just turn the CAPS LOCK off - makes it a little easier to read [img]images/icons/grin.gif[/img]

This is what the guy had listed on his site which is why I think it was the same boat:
"23' Sea Craft 1973 188 hp Mercruesers I.O.-Cuddy $7,000 Martha's Vineyard M " Sounds like yours... This was the site it was on : http://www.marinebrokerage.com/boats.html

Are you looking at totally new power? Or new motor/rebuilt drive? Would it be any cheaper having done in NB instead of Island?

Good luck...

John

Re: TSUNAMI I/O repower
 

Chris,
congrats on your new boat.I bought a74 tsunami 23 in 1997.Had the original 351 ford motor and mercruiser i/o.got 3 seasons out of it before the transom assembly fell apart.I repowered with a 2000 mercruiser 260 efi with alpha gen ll drive.The boat needed extensive glass work(new transom,engine stringers ,and deck repair) before the new motor went in,but it turned out great.I run her at 3200 rpms,cruises at 23-24 knots,burning about 7.5-8 gph.Very economical,quiet,all around solid power package.Feel free to e-mail me ifyou have any questions about your project at bobfish21@aol.com. Good luck!
oh,and by the way,if you think your transom's ok,dont bet on it-at that age,theres sure to be water intrusion and very likely substantial rot. dont take a chance putting a brand new powerplant in a boat thats not structurally ready to handle it.

Re: TSUNAMI I/O repower
 

John this sounds like the same boat but I bought it from a friend who is building a house and was not able to fix it. I actualy know the last three owners and I think it has been on the Island since 1986. In the last nine years it has only been in the water for two summers. Bob I have pulled out the motor and outdrive plus the bolts holding the swim ladder and the transom is dry and sound. Thanks for the info on the 260 HP I/O. Chris

Re: TSUNAMI I/O repower
 

Sounds good Chris - looking forward to seeing some pics...

With the tiny difference in price and no weight penalty why don't you just put the 5.7 (350CID) motor in instead of a 5 liter? That little extra go juice might be worth it...

Good luck

Re: TSUNAMI I/O repower
 

Chris,
I agree with John. That 5 liter may be a little strained under the load. Any idea how well it ran with the 188hp (must be a straight 6?)? I would think that engine was under quite a bit of strain.

BTW, I fish the Derby every year so I'll have to keep my eyes peeled for your boat. What's the hull color? Where are you keeping it?

Re: TSUNAMI I/O repower
 

Scott

The 188 HP is a ford base 302ci block V8. The previous owner said that it went OK. The reason I want to go with the lower HP is that my son is mostly going to be using the boat and I don't want it to be to fast! The hull has been hand painted black and we will keep it in Tashmoo. Thanks

Re: TSUNAMI I/O repower
 

Chris - if you want to keep it a little meaker, look into the slightly modded 4.3 V6 package. It's already lighter than the 8, it's a common block as it's a chevy 350 missing 2 cylinders, a great motor - I had one from 88-92, and can be easily tweaked to 220HP carbed or stock EFI. With the EFI V-6 you'll get much better fuel economy, less weight in the stern and might not be too much more than the carbed 8... Worth looking into.

Good luck

Re: TSUNAMI I/O repower
 

The 5.7 260hp motor will probably add substatially to the overall resale value of the boat vs. the 4.3. That 4.3, while a good motor, cannot match the torque of the 5.0 or 5.7 v8. Load that boat up with 80 gal's of fuel,fishing tackle and 4 guys, that thing will be a dog out of the hole. You are talking about 4500 lbs loaded. As for economy, a 5.0 or 5.7 will loaf along at 24kts while the 4.3 will probably buzz at 3800 rpm to maintain that, pushing an obviously smaller prop. If you don't trust your son to drive the boat responsibly, then don't let him use it. Go for the 5.7.

Re: TSUNAMI I/O repower
 

OK, so here is my 2 cents, Briguy is making the right call here, if you get less than 5.7 you'll never get that bitch out of the hole with a full load, you need the torque from the 5.7 and you then cruise all day at 22-24 kts. with MPI at 3200 and burn 8 GPH...you don't want to under power her. I put in a 454 Vortec and have no regrets

Re: TSUNAMI I/O repower
 

I stand corrected [img]images/icons/wink.gif[/img]

My choice - if it were mine with a few $$ to spend - for an I/O would be a fuel infected 350. That 454 would be a couple hundred more pounds in the stern but it would certainly move out. The 4.3 option is purely the low end of the HP ticket out of all these engines. Just my thinking. These guys are right in that a 350 would be the better all around choice....

Re: TSUNAMI I/O repower
 

Chris:

I am also a new member to the CS site. This is my first time responding to a question on the forum board - hopefully I have done it correctly (I am semi-literate with computers). First of all, I am amazed at how much information is available on this site - "Trayder" has done an incredible job. To that end, if you have not already, I suggest going back over old posts for additional information.

I am responding to your questions between meetings and am pressed for time right now (though you can see where my priorities are) but felt compelled to since I am the original owner of a 1978 Sceptre, and have repowered once already with a MerCruiser 454/Bravo One package. Will be happy to share my two cents - however, it might be easier by telephone or I will try to e-mail you later. However, one thought now is that I strongly agree that a 350 block/260 hp would be the minimum to go with. My original pwoer was a 305/230 hp and felt it was underpowered. Also, going with a Bravo 1 vs. Alpha has many advantages. Good luck and feel free to pick my brain further.

Re: TSUNAMI I/O repower
 

Chris,
I have the boat your'e thinking of building and the 350 efi motor is a better choice.Mine cruises 22-24 kts at 7.5-8 gph;avery comfortable and safe speed.These boats actually ride better at higher speeds-when i occasionally push it up to 4600 rpms(just for a mnute or two) the boat seems to benefit from the increased air the hull traps between deadrises,runs38kts top end.Youll be very happy with its cruising speed performance.If I had to do itb again, I mightb opt for the bravo lll duoprop-no torque steer,slightly better numbers at cruise,more control in reverse.Also ,ive been told with a bravo you can run a raw water pickup and sea strainer setup with the motor's water pump handling cooling chores rather than the outdrive-a big help if ,like here on the great south bay,eel grass and plastic bags wrapped around your lower unit can really ruin your day!

Re: TSUNAMI I/O repower
 

I have a 4.3 Volvo D/P on a 20 cutty which is a lot for the boat. Others I know with the same on a 23 have made comments that they wished they went bigger. Adequate but when heavily loaded, they wish they had more power/speed.

You might want to look into getting a heat exchanger (fresh water cooling system) on your motor. This may be a little costly but I found that this keeps the motor in good condition running antifreeze and with about 1,500 hrs, have not have any major problem yet....knock on wood!... .

Good luck on your rebuild!

Re: TSUNAMI I/O repower
 

Thanks everybody for all the input. I think at this point money is going to be what determines what motor I buy. I think I will stick whit the alpha drive because that is what was in there and I have another boat whith that same unit. I am glad to here that people are getting over 3 MPG out of this boat since gas here is over $2 a gallon and climbing. Thanks.

Re: TSUNAMI I/O repower
 

Place down here called affordable marine that is very cheap on brand new moters , long block, short block , turn key, whatever. Not sure he ships but he probably would. I bought my long block PCM 350/280 from him for 2300. 5 years ago and still kicking strong. i did go with freshwater cooling as well.If Anyone wants the phone number I will post it.

By the way,dont want to offend anyone and if I do I apologise but I never heard of a place called "Gay Head"? I will leave it alone.

Re: TSUNAMI I/O repower
 

Miles- Gay Head is a spot on Martha's Vineyard, well known for its cliffs, great fishing, and more recently the location of John F Kennedy Jr.'s Plane crash ( A SeaCraft 20 Sportfish owner by the way )

Here is a pic:

http://www.mvisland.org/gh%20cliffs.jpg

Re: TSUNAMI I/O repower
 

Beautiful place!!! thanx for the pic. Didnt know that Jr. was a fellow SC'r.

Re: TSUNAMI I/O repower
 

Oh, I can see it now. Some wise guy visitor to the sight is going to read this thread and sign on a member name GHOSTOFJFKJR.

I wonder who owns that JFK 20 footer?????
I guess he should have stuck to boating.

Re: TSUNAMI I/O repower
 

Gay Head (know called Aquinnah - it's indian name) is one of the best bass surf & boat fishing places in the world, and right next to one of my favorites, Squibby [img]images/icons/grin.gif[/img] , Cuttyhunk, & Devil's Bridge

Gay Head:

http://www.striped-bass.com/Images/gayhead3a.jpg

Squibnocket (where JFK's family vacation home was) :

http://www.striped-bass.com/Images/squiby7a.jpg

Chris - you must have read Post's "Reading the Water", right?

[ February 01, 2003, 02:20 PM: Message edited by: John R ]

Re: TSUNAMI I/O repower
 

It's been a while! Had to redo transom it was very wet and had a little rot in places that I did not expect. Wish it had more rot because the good wood was hard to get out. Did it from outside because it looked easier than removing top rail ect. and I liked having work area out in open. I now see why transom should be thourly checked even if it looks good. Pulled fule tank and it is original and looks good but still am going to replace. Decks are strong and dry. Area in fule tank cavity is dry and sound. Got a new non current year 240 efi merc with brovo-1 drive which I plan on installing in two weeks. Boat will be used mostly by my 16 year old son for commerical fishing (scup, sea bas, stripe bass, ect.) Thanks for all info posted on this site about SC it has been very helpful.

Re: TSUNAMI I/O repower
 

For just under 8000.00 you can not go wrong with the 5.0 liter alpha package. The 5.0 will run all over thae old ford that is in there now. If you son is using the boat then thats what I would with. MerCruiser makes a alum. 4 blade prop that will do fine getting it out of the hole for ya. This engine package is our bread and butter package. We install around 7 per year and just do not see them back with any problems. THe customers are more then happy with them. None have gone into a seacraft. THe largest boat that we installed on in was a 24 chris craft lancer that ran great when we were done with it. If your looking for good over all performance and a good price then go with the 5.0 package.