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-   -   3 x 300 yamaha outboards (https://www.offshoreonly.com/forums/general-boating-discussion/66585-3-x-300-yamaha-outboards.html)

t.rae 12-17-2003 10:48 PM

3 x 300 yamaha outboards
 
I have a 36' yellow fin center console fishing boat with 3 x 300 yamaha hpdis. I can get 68 mph on gps turning 5800 rpms with a light load. I get 64 mph at 5450 with a heavy load. I'm turning a 23 mirage prop. I'm going to get low water pickup on the motors, because the middle motor runs hot at W.O.T. after reading some post on the pickups and props one name kept popping up " Houston Propellers" I called them and Darin said by labbing the props I could get 3mph more. So I sent him the props. We will see, I sure hope so. Will I gain any speed from the low water pickups at these speeds? Does any one have any experience with outboards with simular speeds.Thanks for any replies.

puder 12-17-2003 10:52 PM

welcoem to the board!

dunno about your pickup question though.

Sydwayz 12-17-2003 10:53 PM

Not sure where you are running at, but LWP pretty much suck ass, er, sand, er both.

You might consider just switching the Center lower to a LWP. That way, in case you get caught in some crappola, and you plug a cooling system with the LWP, you only plug 1 of 3. As far as the other two... if they ain't broke, don't fix 'em.

I have an I/O Bravo1 drive with LWP, and please take my advice, considering I have literally filled my entire block with James River mudd, to the point I could remove the thermostat on top of the engine, and pull the mud out with a spoon just like a Jello pudding cup.

Madcow 12-17-2003 10:58 PM

Where's wicked won when you need him? He has a 36 Concept with tripp Yamahas.

Audiofn 12-17-2003 11:01 PM

Low water pick ups with outboards are not such a issue as you can trim them up when in shallow water and still control the boat. ESPECIALLY if you have tripples :D What was your water preasure on the middle motor? Was it lower then the other two? If so then you are to high in the middle motor. Are your three motors straight across? If so is the middle motor a long shaft? The low water pick ups can cause you to loose speed as the bullet is longer and causes more drag. HOWEVER if you get the low water pick ups you can lift the motors up a higher and gain speed.

Jon

t.rae 12-17-2003 11:15 PM

the center motor is a long shaft. I don't have a pressure gage, but the temp alarm sounds off. I had a yamaha tech put a computer on the motor while running, thats how he determined the water problem. I agree with the "ain't broke don't fix it" but figured if I had to do one do them all and raise the motors. I also don't want to waste money if it's not going to help the speed.

t.rae 12-17-2003 11:17 PM

catmando, yes it weighs about 14,000 lbs. 10'6 beam.

Ted G 12-17-2003 11:22 PM

I would suspect you would see very little speed improvement from raised motors and your time to plane might be lengthened considerably. Raising X dimension is much more beneficial at higher speeds when you can semi-surface the props. But there is almost always an increase in time-to-plane due to the higher props.

Ryan Beckley 12-17-2003 11:43 PM

You really aren't too far off. Wylies 300x boat ran in the LOW 70's. I know the 36' Concepts aren't quiet at this speed yet either. I also know that YAMAHA is having Pickup problems with some similar boats. Remember this is a REAL fishing boat isn't it like almost 11 feet wide.

t.rae 12-17-2003 11:54 PM

Ryan,What would you do then? LWP the center motor and leave the rest alone? What about lthe labbed props? "off the hook"


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