2005 23 GULF STREAM SINGLE 250 YAMMI

[USSBATHTUB]

I'M JOEY AND AM HAVING TROUBLE STAYING UP ON PLANE AT 4500 RPM ( THIS RPM IS WHAT GRADY TOLD ME TO CRUISE AT ) IT SEAMS THAT IF THERE IS A LITTLE ROLL OR VERY SMALL CHOP I COME OFF OF PLANE. I HAD THE ENGINE COMPLETELY CHECKED EVERYTHING IS GOOD, COMPRESSION & NEW PLUGS.
I KNOW THAT I HAVE THE SMALLER LITER ENGINE I'M NOT SURE THE SIZE IN LITERS I BELIEVE THEY MADE 2 DIFFERENT SIZES BUT CAN'T FIND THE SIZES. ANY HELP ON MY PLANNING PROBLEM OR SUGGESTIONS WOULD BE GREATLY APPRECIATED THANK YOU ALL
JOEY CIRACO

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[Wanago]

Joey:
I am in the process of converting my 232 Yamaha F250 to a Yamaha or Susuki 300. The F250 is a 3.3 liter motor and I have the same problems you are having. There is nothing wrong with the motor, it is just too small. The Yamaha 300 is a 4.2 liter engine. Grady now uses this motor for new models in single. A friend of mine installed a Susuki 300 with a duo prop and is pleased with performance. My interest in Yamaha 300 is 4.2 liter performance and lighter weight (about the same as F250). The few reports I have found said the performance of the boat was much better and worth the conversion.

 

[DennisG01]

Joey, can you get the engine to full RPM - at or near it's MAX RPM? Is it 5,500? That's the first thing we need to verify. Secondly, yes, it's smaller than most would like, but it should still work. And there are ways to make it work so you don't have to buy a new engine.

--What kind of load in the boat are you running?
--Is the hull bottom nice and clean? ANY growth, however little, will drastically affect performance.
--Is the prop is excellent shape? What pitch (this matches up with the RPM question).
--I see you joined here a year ago... how long have you had the boat and have you always had the problem?
--Are you properly using your engine trim AND trim tabs?

 

[USSBATHTUB]

I WOULD LIKE TO THANK BOTH OF YOUS FOR HELPING ME, ANY HELP WILL BE GREATLY APPRECIATED
TO DENNIS GO1 FIRST: 2005 23 FT GULF STREAM .. . I DON'T HAVE VERY MUCH IN THE CABIN OR ON THE BOAT
THE HULL IS CLEAN AND PAINTED WITH ABLATIVE PAINT IT STAYS VERY CLEAN
ACCORDING TO GRADY ITS THE CORRECT PROP IT HAS NO DINGS OR DENTS FEELS LIKE BRAND NEW
I ONLY HAVE THE BOAT SINCE AUG. 2018 I PUT 1300 MILES ON THE BOAT LAST YEAR. LIKE I SAID BEFORE THE HULL IS CLEAN AS A WHISTLE
I'M LEARNING TO TRIM THE ENGINE BETTER NOW... I VERY RARELY USE MY TRIM TABS IT SLOWS THE BOAT DOWN A LOT THEY ARE VERY CLEAN.
TO WANAGO:: THANK YOU FOR YOUR RESPONSE I APPRECIATE IT, I AM HOPING THIS ENGINE LAST ME A WHILE LONGER IF I HAVE TO CHANGE IT YES I WILL PUT A 300 ON IT HOPEFULLY A YAMAHA. I HAD 3 SUZUKIS ON MY CENTER CONSOLE FOR 20 YEARS THEY WERE GREAT. I'M JUST GOING KEEP MY FINGERS CROSSED AND HOPE THIS 4 STROKE YAMAHA LASTS I ONLY USE YAMAHA OILS AND MY MECHANIC DOES ALL THE RECOMMENDED MAINTENANCE USING ONLY YAMAHA PARTS.
I WOULD LIKE TO THANK YOU BOTH FOR YOUR HELP.... JOEY

 

[DennisG01]

Joey, what's the maximum RPM you can achieve (and GPS speed) when you're going all out? No trim tabs and keep trimming the engine up till speed no longer increases or the prop starts to ventilate.

Tabs should NOT be dropping speed all that much at cruising speeds. They are, however, a HUGE help to hole shot, staying on plane at a slower speed and even performance and ride quality. From what you've written, it sounds like the solution might simply be learning how to trim the engine and tabs better... in other words, a FREE fix! Use those tabs! It's like a having a great tool in your toolbox but never using it.

FYI... using all caps in a forum is like "shouting" (Which I know you aren't actually intending to do)

 

[seasick]

I am not sure if you are talking about a new problem or one from day one. Did this problem occur last season when you boated 1100 miles?

What revs do you need to run to get on plane as opposed to what revs you need to stay on plane. Something sounds strange.
Have you noticed any cases where the revs seem to go up quickly buy the speed doesn't?
Can you tell if the bow is in the water when you get on plane?(plowing)

 

[Harpoon]

Joey, I had the same boat and motor package. That should not be happening. Is this boat new to you ? Or is this something that just started....
I put a 15.8X15P Quicksilver and made that boat jump on plane, better cruise speed and fuel mileage.

I also think something is strange there. I had a Zuke once that did that and the prop hub was slipping slightly.
Barnacles or excessive drag will also cause this ....

However if this thing is new to you it sounds like a mis-matched prop, specifically a small diameter or over pitched.

 

[DennisG01]

a mis-matched prop, specifically a small diameter or over pitched.

Hence the remaining (yet unanswered )question about the WOT RPM - which should help narrow down the possibilities.

 

[USSBATHTUB]

THANK YOU EVERYONE FOR YOUR REPLY'S AND HELP
I CALLED UP GRADY WHITE, I ASK THEM WHAT WAS THE CORRECT PROP FOR MY ENGINE, SHE ASKED ME FOR MY ENGINE SER. # AFTER SHE CHECKED I MATCHED HER NUMBERS WITH MY PROP #s THEY WERE EXACT. SHE ALSO STATED THAT I SHOULD CRUISE AT 4500 RPM'S AND THE BOAT SHOULD DO APPOX. 29 MILES AN HOUR, WITH A HALF A TANK OF GAS AND ONLY ONE PERSON. MY BOAT DOES 22 TO 24 KNOTS @ 4500 WHICH IS CLOSE I LIKE TO KEEP MY TANK TOPPED OFF. THE ENGINE RUNS GOOD I STAY ON PLANE MOST OF THE TIME BUT WHEN I HIT A LIL CHOP I HAVE TO GO TO 47OO RPMS OR I COME OFF PLANE
I WILL USE MY TRIM TABS AND SEE IF SHE STAYS ON PLANE BETTER.

WHEN I'M ON PLANE MY BOW IS NOT IN THE WATER & I'M NOT PLOWING. MY PROBLEM IS THAT I HAD A 21 FT. HYDRO SPORTS FOR 30 YEARS WITH A 200 HP 2 STROKE ENGINE THE BOAT FLEW AND WOULD STAY UP ON PLANE AT 3300 OR 34OO RPMS DEPENDING ON THE SEA CONDITIONS, I'M REALIZING NOW THAT I'M JUST NOT DOING A LOT OF THINGS CORRECT. I WANT TO THANK ALL OF YOU'S FOR YOUR HELP.