23cc transom rebuild and f350 repower

Capt_Mac · #1 08-17-2010, 09:16 PM

My question is about a 1986 23cc tsunami(tsunami marine) which is kinda similar to the older seacrafts. I am having the transom enclosed with a livewell mounted on the transom, then I will have a bracket installed suited for twin motors, then I will have a single yamaha f350 30" motor installed with all of there new gauges, controls, etc. Would anybody know how this boat will perform or know of anybody that has a similar setup? Any information, ideas or suggestions would be great. Thank you

Old'sCool · #2 08-17-2010, 09:34 PM

At ~ 850# w/prop it's a heavy motor. Add bracket and bait water it's a lot of weight. Post pics!!

Capt_Mac · #3 08-17-2010, 09:41 PM

Currently I have a floor livewell and a 2001 250hp on the transom, I am having Hermco do the work and he advised to put a twin bracket for that big single motor, I have seen people with twin 4 strokes from 150hp-200hp on 23 boats and thats gotta be around 1000-1100 lbs right there. I haven't spent any money yet and open to suggestions.

McGillicuddy · #4 08-17-2010, 10:25 PM

If 4-stroke is a must, consider that 300 hp Verados and Suzukis are about 220 lbs lighter, and a 350hp racing verado is about 200lbs lighter than the f-350. Are you dead set on the Yamahas? Seems you're losing the weight to hp battle w that motor...

Capt_Mac · #5 08-17-2010, 10:49 PM

Chuck, I'm not so much concerned about top end but more about cruising speed around 40 mph through out the keys, crystal river, daytona, and long runs on flat days out of cape canaveral. I like my motor to be big and powerful and running at a lower rpm, plus at times I'll have 8-10 people on the boat with a live well full of scallops or lobster and my current 250 struggles to get up on plane because of the weight. I am a yamaha fan and will continue to support there products(my personal opinion). From what I understand the thrust that this motor is putting out I don't think 200lbs is going to make that big of a difference, not quite sure though.

McGillicuddy · #6 08-17-2010, 11:26 PM

Roger that, Capt Mac. Now better understanding your utility, you're probably right, 200 lbs is probably irrelevant. Trusting your power is peace of mind - especially when numerous passengers are aboard. You like and trust Yamaha, by all means stay w/ Yami. Post a picture of your Tsunami. We don't see many out west. Best wishes on the re-power.

Capt Chuck · #7 08-17-2010, 10:16 PM

I have a friend with a 23' Tsunami. It's a heavy foam filled rig for sure. You will have NO problem supporting the weight of a 350HP since Don has recomemnded the double bracket.
I question the big HP as my friends 225hp has plenty of torque and at top end walks away from my single 250HP SeaCraft. I thinks he carries 170 gals of fuel also

ct9amr · #8 08-20-2010, 08:13 PM

I know its not a seacraft but I have a 23ft contender and recently put a Yamaha 250 on it.
It needs a little prop work but with the old 225 merc prop she runs 45 mph top speed fully loaded.
The cruise speeds are off due tot he wrong prop but I fine it plenty to push this hull.

No problem getting on plane with 4 adults and 5 kids with lots of coolers and toys we take to Egmont Key for the day.