232 Gulfstream: Props & Motor Height...

[Keitha]

I recently bought a 232 Gulfstream - 2007 with twin F150 Yamaha motors
I'm surprised that I can't seem to find much data on how everyone is running their boats.
My boat came with 13 3/4 x 17 (17m) props on it with the motors in the second from lowest mounting height (top mounting bolt is in second from top spot).

I need more time on the water to log performance stats, but curious how others have their Gulfstreams set up. Has anyone experimented with raising the motors?
I will reply back once I get some good performance logs recored.

thanks,
Keith

 

[leeccoll]

Keith,

Welcome to the site!

I own a 228 and raised my engine up to the highest slot. Seems like every owner has raised the engine up one or more spots that had an issue with performance.

Pretty easy to see where your anti ventilation plate is when on plane. Just do it safely if you are alone. You want to see it skimming the waters surface, if it is not, need to adjust the height of the motor.

Again, usually it seems most need to raise their engine height to increase performance.

Lee

 

[Keitha]

Thanks for the welcome and the reply
Yah, This is my first twin outboard boat. I am coming from a 18' BW Outrage. That was a pretty simple boat to figure out. I'll log a bit more time to get a baseline and observing the Cavitation plate, then see how she does lifting a notch.

 

[DennisG01]

Like Lee said, observing the anti-ventilation plate is a great way. If need be, use your phone and video it. Another easy way to check is to just see what kind of RPM's you get at WOT and trimmed up as high as possible till ventilation or no more speed increase. If you can get near the max spec for your engines, you're doing good. "Tests" are done with a light load - but you may prefer to do this with your "normal" load - that's your call.

 

[coldpizza]

I'd suggest see what WOT and RPM your boat can get, and compare that to what the Yamaha manual says the operating range of RPM is. Want to get close to max as possible. You may need to play around with trim different times to see what is affected by trim. Within using the trim tabs, I tilt the motors up enough to 'porpoise' just a little, and then drop down to stop the 'porpoising'.
With all that said, I am still fine tuning since I've changed from the larger 200's to the 4-inline 200's. They are much lighter than the previous motors.
That's my $0.02

 

[Keitha]

I'd suggest see what WOT and RPM your boat can get, and compare that to what the Yamaha manual says the operating range of RPM is. Want to get close to max as possible. You may need to play around with trim different times to see what is affected by trim. Within using the trim tabs, I tilt the motors up enough to 'porpoise' just a little, and then drop down to stop the 'porpoising'.
With all that said, I am still fine tuning since I've changed from the larger 200's to the 4-inline 200's. They are much lighter than the previous motors.
That's my $0.02

What Props are you running?
What motor Height?

 

[Keitha]

Is anyone running 4 Blade props with F150 motors on a Gulfstream?

 

[coldpizza]

Yamaha Reliance Series 14-1/4" diameter, 18-M pitch. Motor bolt location is second hole from top.
I am getting 5400 rpm, trimmed high and flat water, 47 mph. Yamaha book says its within the operating range but I'd prefer to be closer to 6000 rpm. Not anxious to buy two new props for the 600 rpms so will be living with it for a well.

 

[Keitha]

CP, Have you tried your motors lifted one hole up?
What is your speed at 4,000 rpm? How about fuel burn at that speed?

I had a chance to open mine up a bit on Tuesday. I was hitting 45mph at 6,000 rpm (p) 6,100 rpm (s).
I am at 28 - 29mph at 4,400rpm - just at 2.0mpg

I would rather see 30 around 4,000 rpm.

 

[Keitha]

Boat just got some new shoos in the form of a set of Yamaha Reliance 13 3/4" x 19" props to try. I'm hoping to get out this Saturday and, weather permitting, try to get some data points.
I'll report back on how they perform.

 

[Keitha]

I got out for some good boating yesterday and had a chance to work these new props. They are definitely an improvement and performed as I hoped.
4,000 rpm = 31 mph (2.3 mpg in calm water)
top end
5,600 rpm = 47 mph (1.4 mpg) (need to put in another WOT run to verify this)

 

[BigD808]

I got out for some good boating yesterday and had a chance to work these new props. They are definitely an improvement and performed as I hoped.
4,000 rpm = 31 mph (2.3 mpg in calm water)
top end
5,600 rpm = 47 mph (1.4 mpg) (need to put in another WOT run to verify this)

Can you post a photo of what hole the motors are mounted on the bracket ?

 

[Keitha]

Can you post a photo of what hole the motors are mounted on the bracket ?

Motors in the second from lowest mounting height (top mounting bolt is in second from top spot). Do you really need a picture of this? Next time I'm at the boat I can take one, but it may be a few weeks.

 

[BigD808]

Motors in the second from lowest mounting height (top mounting bolt is in second from top spot). Do you really need a picture of this? Next time I'm at the boat I can take one, but it may be a few weeks.

Thanks. So on the motor side the mounting holes are second from lowest, on the bracket side are they on the top bolt hole, or on second bolt down from the top?