NEED INFO...HELP

WAHOONBOX · 07-06-2005, 11:09 AM

I JUST RE-POWERED MY 94 GRADY SAILFISH....

TWIN 140 SUZUKIS 4 STROKE..........NEW STEERING ...THE WHOLE PACKAGE.......

FISHED THE FIRST TIME YESTERDAY.......................

TROLLING SPEED WAS 5.5 KTS ......@ 1900 RPMS

...............................6.2 KTS .......@ 2000 PLUS OR MINUS A HAIR

THIS SEEMS VERY HIGH RPMS TO ME

IDEAS? SUGGESTIONS? OR AM I REACHING FOR SOMETHING THAT IS NOT OUT THERE?

HOW 'BOUT IT YOU GHURU'S OF POWER.........HELP ME MAKE IT THROUGH THE NIGHT HERE!

Glenn W · 07-06-2005, 11:21 AM

That does seem very high. What are your RPM's at WOT? Maybe you can get by with larger pitched wheels, which will increase your trolling speed. I assume you had the engines trimmed all the way down and your tabs all the way up.

74Formula233 · 07-06-2005, 11:43 AM

Marty, how's your RPMs at WOT? (Speed, just curious)

Are the RPMs within range? Like Glenn said, you may need to demo a few props to fine tune her and then buy what works best....

Holy Smoke · 07-06-2005, 01:27 PM

Wahoo,

I have a 25 mako cuddy with the same motors and I am running
14x22 ss Suzuki props.

1500 rpms 6.3 knots
2000 7.2
2500 8
3000 10
3500 15
4000 23
4200 27
5900 37

That's on a heavy boat (fuel, ice, 3 guys ready to fish)

Looks like you are running the 14x18 props, On your boat you most likely
be happiest with the 14x20 or 14x22. I went with th 22 for a little higher
cruise speed at the expense of hole shot.

MakoMike · 07-06-2005, 02:09 PM

Marty,
Sounds like you need different props.

matey1 · 07-06-2005, 02:51 PM

Marty, i would make sure your rpm's are correct at wide open throttle. thsi is more crucial than your trolling speed rpm's. you should be just at your motors rated wot limit. if that is okay it may be a matter of finding the sweet spot for the new motors versus speed. sometimes on my boat it seems like i run a little slower than my buddies but i get a better hook up ratio cause i feel like i am in my sweet spot for my motor.

AhiSlayer · 07-06-2005, 03:36 PM

Aloha!
Yer not far off at all Marty. Grady is a heavy boat, ya had a full crew, tanks etc.
That's about what it's gonna be, You will see a big difference in ride, especially top end speed with an empty boat

Two inches in pitch will getcha about 3 ta 400 rpms at best.
The test..
Run the boat fully loaded to Wide open throttle. There should be no surge in the engines as you accelerate. When ya reach WOT read the tachs. Theyy should be within 200 rpms of the manufacturer recommendation.

If the tachs are above or below ya need ta change props,,,Think of a prop as a wood screw. As the scew turns it moves ahead or into the wood. A prop turns in water the same way and moves ahead bringing the boat with it. The angle of the scews threads determine how far ahead it moves with each turn.

The angle corresponds to the pitch. The greater the pitch the more the propshould move ahead with each turn,,But the harder it is to turn. Gotta compromise.

If the specs call for 5500 WOT and yer getting 5000 with a 19 inch pitch ya need ta go to 17, more easy fo turn.

More stuff ta confuse ya...The heavier the load the more diameter is needed to push it, so ya need less pitch to get yer WOT right. I suspect yer diameter is right

If the Wot is good but yer speed is too slow ya got too much prop slippage. Slippage is the difference between the theoretical distance the boat should move and how far it actually moves with each turn of the prop. If yer slippage is more than 25% ya may need a bigger blade or a blade with more cup not more pitch. Cupping the prop helps prevent cavitation. Cavitation is when yer boat gives ya sudden surge on a tight turn. Caused from the prop sucking air instead of corkscrewing the water.

Remember to allways test the pops with the boat fully loaded.

Doesn't sound too high to me though, maybe a little if you think so, you know yer boat better than I do.

cheers
ahi

Most props come in two inch increments, it used ta be stainless even and aluminum odd increments, now they mixed it up... But pitch is pitch wether it's stainless of aluminum

WAHOONBOX · 07-06-2005, 03:43 PM

I GIVE THIS 5 STARS NOT FROM MY QUESTION BUT FOR YOUR ANSWERS!!!! SMOKE,MAKO, FORM', AHI , MATEY AND GLENN......THIS IS WHAT I EXPECT FROM THE SFC CREW!! WORLD CLASS!

NOW WHEN I GO BACK TO THE DEALER, I'LL APPEAR TO KNOW WHAT THE HELL I'M SAYING........

I DO A FAIR JOB IN THE PITS......BUT NOT UNDER THE HOOD!

ANYMORE SUGGESTIONS ? LOAD ME UP GUYS!! ITS MY TURN TO GO TO SCHOOL............

HOLEY SMOLEY....I KNEW YOU GUYS WOULD COME THROUGH!

AhiSlayer · 07-06-2005, 03:52 PM

I keep a fuel log. Compair to other boats. If yer over 10 bucks an hour for yer boat, lighten the load.
ahi

Holy Smoke · 07-06-2005, 03:57 PM

Wahoo,

Our choices are limited for non OEM prop's.

Until the aftermarket catches up we are "stuck" with Suzuki props.

07-06-2005, 11:09 AM	#1
WAHOONBOX I'M SPEECHLESS Join Date: Jan 2005 Location: MOREHEAD CITY NC 28557 Posts: 15,286 Credits: 52,032.0 Boat: I AM A FREELANCER Home Port: MOREHEAD CITY, NC Best Catch: PONEYTAIL Occupation: OFFSHORE MATE VIDEOGRAPHER	NEED INFO...HELP I JUST RE-POWERED MY 94 GRADY SAILFISH.... TWIN 140 SUZUKIS 4 STROKE..........NEW STEERING ...THE WHOLE PACKAGE....... FISHED THE FIRST TIME YESTERDAY....................... TROLLING SPEED WAS 5.5 KTS ......@ 1900 RPMS ...............................6.2 KTS .......@ 2000 PLUS OR MINUS A HAIR THIS SEEMS VERY HIGH RPMS TO ME IDEAS? SUGGESTIONS? OR AM I REACHING FOR SOMETHING THAT IS NOT OUT THERE? HOW 'BOUT IT YOU GHURU'S OF POWER.........HELP ME MAKE IT THROUGH THE NIGHT HERE! __________________ I STRONGLY SUPPORT: DEEP DIVING AND EASY TRIPPIN' OLD SALTY PLANERS FINRAZOR RODS & THE ABSOLUTELY DEEPER ATTACK WEAPON: SNIPER PLANER RODS THE GIANT BLUEFIN TUNA HEART STOPPER: POON HARPOON

07-06-2005, 03:43 PM	#8
WAHOONBOX I'M SPEECHLESS Join Date: Jan 2005 Location: MOREHEAD CITY NC 28557 Posts: 15,286 Credits: 52,032.0 Boat: I AM A FREELANCER Home Port: MOREHEAD CITY, NC Best Catch: PONEYTAIL Occupation: OFFSHORE MATE VIDEOGRAPHER	5 STAR ANSWERS I GIVE THIS 5 STARS NOT FROM MY QUESTION BUT FOR YOUR ANSWERS!!!! SMOKE,MAKO, FORM', AHI , MATEY AND GLENN......THIS IS WHAT I EXPECT FROM THE SFC CREW!! WORLD CLASS! NOW WHEN I GO BACK TO THE DEALER, I'LL APPEAR TO KNOW WHAT THE HELL I'M SAYING........ I DO A FAIR JOB IN THE PITS......BUT NOT UNDER THE HOOD! ANYMORE SUGGESTIONS ? LOAD ME UP GUYS!! ITS MY TURN TO GO TO SCHOOL............ HOLEY SMOLEY....I KNEW YOU GUYS WOULD COME THROUGH! __________________ I STRONGLY SUPPORT: DEEP DIVING AND EASY TRIPPIN' OLD SALTY PLANERS FINRAZOR RODS & THE ABSOLUTELY DEEPER ATTACK WEAPON: SNIPER PLANER RODS THE GIANT BLUEFIN TUNA HEART STOPPER: POON HARPOON

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07-06-2005, 11:21 AM	#2
Glenn W Motor Mouth Mega Poster Join Date: Jan 2005 Location: Richmond, Va Posts: 3,732 Credits: 2,117.0 Occupation: Moonbat	That does seem very high. What are your RPM's at WOT? Maybe you can get by with larger pitched wheels, which will increase your trolling speed. I assume you had the engines trimmed all the way down and your tabs all the way up.

07-06-2005, 11:43 AM	#3
74Formula233 I think Admin is going to let me have this space Join Date: Mar 2005 Location: Southern Rhode Island Posts: 2,087 Credits: 1,241.8	Marty, how's your RPMs at WOT? (Speed, just curious) Are the RPMs within range? Like Glenn said, you may need to demo a few props to fine tune her and then buy what works best....

07-06-2005, 01:27 PM	#4
Holy Smoke Stop staring at my Avatar. Join Date: May 2005 Location: Apex, NC Posts: 391 Credits: 1,335.7 Occupation: Peddler	Wahoo, I have a 25 mako cuddy with the same motors and I am running 14x22 ss Suzuki props. 1500 rpms 6.3 knots 2000 7.2 2500 8 3000 10 3500 15 4000 23 4200 27 5900 37 That's on a heavy boat (fuel, ice, 3 guys ready to fish) Looks like you are running the 14x18 props, On your boat you most likely be happiest with the 14x20 or 14x22. I went with th 22 for a little higher cruise speed at the expense of hole shot.

07-06-2005, 02:09 PM	#5
MakoMike Crab mustard is good Join Date: Sep 2004 Location: Exeter, RI Posts: 680 Credits: 1,217.6	Marty, Sounds like you need different props.

07-06-2005, 02:51 PM	#6
matey1 Sit down Shut up And fish Join Date: May 2005 Location: middletown, DE Posts: 520 Credits: 1,219.1	Marty, i would make sure your rpm's are correct at wide open throttle. thsi is more crucial than your trolling speed rpm's. you should be just at your motors rated wot limit. if that is okay it may be a matter of finding the sweet spot for the new motors versus speed. sometimes on my boat it seems like i run a little slower than my buddies but i get a better hook up ratio cause i feel like i am in my sweet spot for my motor.

07-06-2005, 03:36 PM	#7
AhiSlayer Crab mustard is good Join Date: Feb 2005 Location: Ya may get bonus letters cuz I'm posting from my cell phone Posts: 873 Credits: 1,282.6 Occupation: pole benda	Aloha! Yer not far off at all Marty. Grady is a heavy boat, ya had a full crew, tanks etc. That's about what it's gonna be, You will see a big difference in ride, especially top end speed with an empty boat Two inches in pitch will getcha about 3 ta 400 rpms at best. The test.. Run the boat fully loaded to Wide open throttle. There should be no surge in the engines as you accelerate. When ya reach WOT read the tachs. Theyy should be within 200 rpms of the manufacturer recommendation. If the tachs are above or below ya need ta change props,,,Think of a prop as a wood screw. As the scew turns it moves ahead or into the wood. A prop turns in water the same way and moves ahead bringing the boat with it. The angle of the scews threads determine how far ahead it moves with each turn. The angle corresponds to the pitch. The greater the pitch the more the propshould move ahead with each turn,,But the harder it is to turn. Gotta compromise. If the specs call for 5500 WOT and yer getting 5000 with a 19 inch pitch ya need ta go to 17, more easy fo turn. More stuff ta confuse ya...The heavier the load the more diameter is needed to push it, so ya need less pitch to get yer WOT right. I suspect yer diameter is right If the Wot is good but yer speed is too slow ya got too much prop slippage. Slippage is the difference between the theoretical distance the boat should move and how far it actually moves with each turn of the prop. If yer slippage is more than 25% ya may need a bigger blade or a blade with more cup not more pitch. Cupping the prop helps prevent cavitation. Cavitation is when yer boat gives ya sudden surge on a tight turn. Caused from the prop sucking air instead of corkscrewing the water. Remember to allways test the pops with the boat fully loaded. Doesn't sound too high to me though, maybe a little if you think so, you know yer boat better than I do. cheers ahi Most props come in two inch increments, it used ta be stainless even and aluminum odd increments, now they mixed it up... But pitch is pitch wether it's stainless of aluminum

07-06-2005, 03:52 PM	#9
AhiSlayer Crab mustard is good Join Date: Feb 2005 Location: Ya may get bonus letters cuz I'm posting from my cell phone Posts: 873 Credits: 1,282.6 Occupation: pole benda	I keep a fuel log. Compair to other boats. If yer over 10 bucks an hour for yer boat, lighten the load. ahi

07-06-2005, 03:57 PM	#10
Holy Smoke Stop staring at my Avatar. Join Date: May 2005 Location: Apex, NC Posts: 391 Credits: 1,335.7 Occupation: Peddler	Wahoo, Our choices are limited for non OEM prop's. Until the aftermarket catches up we are "stuck" with Suzuki props.