Panicking please help

[SkunkBoat]

I did it before.
My dealer said if you don't want to wait, take em off bring em in and I'll give you the new ones to try...
It shouldn't cost you anything to test props and get the right ones. Thats my experience.
I can't imagine a dealer just saying one size fits all..there you go...
If he absolutely won't test props I would tell him to refund your prop money and get Powertech props

Higher pitch will lower your max rpm but increase your cruise speed and top speed and probably your mpg @ cruise.
...to a point... at some point the higher the pitch will cause you to bog down on takeoff. Its a trade off.

When you gun it the motors should load just slightly. I'm guessing yours spin up like mine did when you push the throttles

test them with a full load of fuel. test them for a day out the inlet in some seas. A 10 minute test run with a 1/4 tank in flat calm in the river means nothing.
Test them with motors all the way down on take off...then raise them as soon as you are up.

Test from a dead stop with them up at cruising trim. they probably spin and maybe won't get you up. Not unusual

Do they raise all the way out of the water? If not I can tell you about that too..

 

[Sparkdog118]

I’m thinking 17 is way too low for twins. I agree with 19-21 to be your ticket. Bow lift style is important. Guessing it to be more towards the 20 to 21 range once you get that bow lift. Your cruise speed would be better than what you are getting. Get them changed out ASAP. Don’t want to be running your motors with not enough resistance on the prop.

 

[Legend]

I had an 4 Gulfstream that was powered by a F225. I read on here that the boat with that engine is underpowered, I never had an issue the 4 guys loaded with ice and gear. Would it have been nice to have more power, of course. I think the twin 140's will be a very nice package

 

[Grief]

I had the boat out today at 5500 rpms im doing 29mph at 6100 rpm im doing about 32 there was 5 people on the boat and about 75 gallons of fuel but when I was coming back though the inlet on a outgoing tide I could barely get the boat to plane off I think im going to need a 21 pitch 4 blade prop

 

[SmokyMtnGrady]

Thanks for the reply should I wait till the 20 hour oil change to change the props or go bigger right away? My dealer is kind of a know it all and keeps telling me the 17 pitch props are good and he puts them on a ton of boats I need to go at him with some info so he doesn't make me look like a moron

I would get it fixed with the right props. The Gulfy is a big girl and while your dealer may know zukes clearly he is under estimating the mass and needs of the Gulfy. I would push to test other props and call Ken . That dude is the man!

 

[SkunkBoat]

The only sure way to know is to try. As I said, I would push the dealer for Suzuki props that work. imo try the 3 blade 14x21 next .That will tell you something.
If its still not up to desired performance consider 4 blades.
If the boat lugs with that, go down to the 14x20.
4 blades are going to cost you but they might be the ticket

Another thing that helped me was a very slight toe in of the motors(props pointed toward each other)
. Might not be relevent to you with a bracket.

 

[SkunkBoat]

I just want to say also...hang in there.... when it all settles out you will have a huge smile from ear to ear.
I just did this with twin DF200s and the disappointment at the first set of props was draining. Coupled with the motor with the steering cylinder did not come up out of the water when raised.
Now I have the right props and the right tie bar and the boat runs GREAT!

 

[magicalbill]

I still say that twin 140's are low HP for a Gulfstream. That said, I agree that you have the wrong props and some improvement can be achieved with the right wheels spinning.

If you had 5 passengers and 75 gallons of fuel in a rough inlet, it would be a bit sluggish even with the right props. I am not qualified to analyze your numbers with correct wheels, but my guess would be a cruise in the hi-20's and a top of 40-41 MPH.

I agree as well that you shouldn't run those new engines with the wrong props for any longer than you have to.

 

[Grief]

Hey guys I haven't updated in a while. So currently now the set up on the new engines is im running 17x20 props and I brought the engines up a hole but runs much much better I can comfortably cruise at 4900-5100 RPM 30mph and at WOT (I can hit 6100) his anywhere from 35-38 depending on conditions, I still think I need to play with but in going to wait till next season. Also it turns out one of my engines was running rough and stalling sometimes turns out it came from the factory with a bad fuel filter and bad plugs so that helped a lot. I havnt tried 17x21 props yet because im worried I might lose to much rpms I might try a 4 blade prop next year. Overall I am happy with 140s Suzukis they only problem im having now is I went with the new Suzuki SMD 7 gauge and it is complete shit my fuel gagues have stop working 3 times already and only the dealer can reset them