Anyone out there with Twin 150 Yamaha Motors?

[Jaizzen]

Looking for some perfomance data from guys running twins on their 23' Tsunami or Sceptre.

Thanks, Jason

[CapeBoater1]

I have a 23 Grady Gulfstream with twin 150 Yamahas. The performance data on that is a cruise speed of 30-33 and top of around 47. The gulfstream has an identical deadrise at the transom and is a heavier boat so your performance would be similar I would "GUESS".

[Jaizzen]

I have a 23 Grady Gulfstream with twin 150 Yamahas. The performance data on that is a cruise speed of 30-33 and top of around 47. The gulfstream has an identical deadrise at the transom and is a heavier boat so your performance would be similar I would "GUESS".

Thanks for the input! I was hoping for a 30 kt cruise. Top end doesn't mean much to me. How about fuel numbers?

Thanks again fot the information.

[peterb]

I have twin 1998 Yamaha 150 Salt Water Series engines. They have carb's and like gas alot. They are on a 23 foot SF SeaCraft. I may average around 1.5 miles per gallon (if I'm lucky).

[Jaizzen]

Thanks for the info. I'll put my numbers up as soon as I splash the boat.

Jason

[Jaizzen]

PeterB, What props you running? What type of load do you carry.

thx, Jason

[peterb]

Jason,

I have stainless steel 17-M props.

For boat weight I come up with around 5,600 pounds

(boat & t top = 3000 pounds) + (2 engines = 838 pounds) + (mostly filles 150 gallon gas tank = 900 pounds) + (3 fisherman and other misc stuff = 600 pounds)

Also, I use 12x12 Bennett trim tabs

What was the question again? Hope this helps.

[Jaizzen]

Thanks for answering my question. I too have the m-17 props. I have the same fuel, same motors (not installed yet). I have a Tsunami. I will be considerably heavier with scuba tanks. Just trying to see if i'll be propped right.

Jason

[peterb]

Oh, and I get up to around 5,400 RPM's at WOT

[peterb]

So what kind of performance numbers did you end up getting?