Man oh man, what a ride.

[bigeasy1]

Well,I finally got a chance to sea trial my Tsunami,and all I can say is "WOW".
It's been fairly nasty on the great lakes(lake Ontario),where I now have the boat.The last few days the seas have been 3 to 8 foot waves very close together,which unfortunately,seems to be the norm,every time I get there.

Today we came in in a very steep chop of at least three footers,spaced very close together,and I,along with my friends,were blown away by the ride.
I was able to get on plane,and ride on top of these without pounding.It was unbelievable,the faster I went,the better the ride actually got.
I did have a couple hard landings,when I wasn't paying attention,and in a bit of a quartering sea,but this boat is everything it's said to be.

I found that the tabs are a huge help for getting the bow down where it needs to be in these conditions.

I have a 350 Mercruiser in it with a 4bbl carb that puts out approx 275 HP.
The one thing that I'm a little unhappy with is that my top speed is only around 33 MPH,at 4400 rpms(that's max rpms),and at about 3400 Rpms,it's around 26 Mph.

I'm spinning a 14-1/2 X 17 prop.I'm wondering if the out drive needs a gear change.
Currently,It's a 1.65 to 1 gear ratio,but my marine mechanic says that I would be much better off with a 1.50 to 1 gear ratio.

Anyone have any advice?would it be worth the cost,and would it improve the performance significantly?.

Anyway,I still can't beleive how awesome the ride is.and I am in my glory with this boat.
If anyone has any input regarding the gear ratio change,it would be appreciated.

[1bayouboy]

I have a 1.5 on a Bravo 1 but it's on an 18 degree deadrise 24WAC (Sportcraft). It has a 350MAG Horizon with a WOT rating of 5200RPMs and I can hit 5150 with a 15 pitch Rev 4 for a top speed of about 41. Cruise at 3600 RPMs is about 27MPH for abou 2.7mpg. Dropping the gear ratio I think will move you to a lower pitch prop to hit your WOT rpms. I don't know that it would improve your overall performance.......maybe Fr Frank will chime in What kind of prop is it??

[McGillicuddy]

Congrats on splashin' her, John. That red Tsunami's gonna be the envy of Lake Ontario. I can't give you much advice on performance, but find out exactly what prop you have and tinker with that first. Also, was your speed reading gps, or paddlewheel; and was it reading knots or mph?

[bigeasy1]

Thanks guys,
The speed was on my GPS. The top speed was about 33.
I probably could have got a little more,if I played with the tabs,but I still don't think it would have increased all that much.

If anyone has any advice regarding an out drive gear change feel free to chime in.

here's a few pics.

[Rich]

Looks Awesome John!

[1bayouboy]

That does just look awesome.....

[Snookerd]

Nothing looks better than an SC that's out in full FISHING MODE. Great shots John!

[ggreeby]

Try different props, They are a lot less expensive than a gear change. What is your engines suggested max RPM? that is avery important factor.

[bigeasy1]

The prop I have on now,is right on,or at least as close as I can get.
I'm hitting my engines max rpms(around 4400 to 4600 rpms),at wide open,and cruising at approx 24-25 mph at 3400 to 3600 rpms.speed is on the Gps.

I'd lose rpms,if i step up to a steeper pitch.My Mechanic,who is a friend of mine,and who would do a gear change for very little money,tells me that 1.50 is the proper gear for that engine and drive,and that the rig would perform better,with a higher top end,and better cruise speed.
He works almost exclusively on I/O powered boats,and I trust him.
He has an upper unit that he would install and let me try out,to see if I like it,at N/C.
He rode on this boat years ago,before i bought it,when it had a 351 Ford in it with a 1.50 drive,and claims it was quite a bit quicker.
The current engine is a 350 with a Edelbrock 4bbl and is in extremely good condition,with perfect compression and very few hours.
It should be equal in hp to the 351 ford that was in it before.

I just think that I should be able to get a higher top end,and a faster cruise at less Rpms.I was wondering if anyone had the same setup.

Here's the pics I deleted by mistake

[ScottM]

John,
The ride really is something. Ten years ago when my father bought his 23' Sceptre, he had stepped up from a 20' Wellcraft V20 CC. That first ride on the SC in similar conditions that you describe was incredible - we braced for re-entry and nothing but a soft landing.

Regarding your speed, I would think you could get more out of that setup. A fellow CSC member and family friend has an '85 Sceptre with a 260hp Merc 350 and Alpha drive. Not sure of RPMs or prop size, but he consistently runs mid 20s cruise and a 40-41mph top end.