Sea ray 300 weekender

[Wingphil]

Hi all
I have an 89 weekender made by searay/Brunswick and am doing a full refit.

One item I want to look at is props.
The boat is pretty standard without generator, two 260 inboard mercruiser a with v drive. Used with two to four people, or will be.
I do not have too much info on its performance as I got it to do full refit and then use.

I am in uk and the cost of fuel would stun all of you in USA. So the purpose of the prop change would be to improve economy.
Obviously any other gain would be nice but ......
Does anyone have any direct experience with these boats, and if not any experts out there who can provide advice?

 

[Bondo]

Re: Sea ray 300 weekender

Hi all
I have an 89 weekender made by searay/Brunswick and am doing a full refit.

One item I want to look at is props.
The boat is pretty standard without generator, two 260 inboard mercruiser a with v drive. Used with two to four people, or will be.
I do not have too much info on its performance as I got it to do full refit and then use.

I am in uk and the cost of fuel would stun all of you in USA. So the purpose of the prop change would be to improve economy.
Obviously any other gain would be nice but ......
Does anyone have any direct experience with these boats, and if not any experts out there who can provide advice?

Ayuh,.... Welcome Aboard,... Yer gettin' ahead of yerself,...

Yer question can't be answered without some numbers to work with,....

I can tell ya that Uppin' the pitch to lower the rpms(ei; fuel economy) will usually cause more problems than any benefit,...

Unless of course it's under-pitched to start with,...

 

[Scott Danforth]

Re: Sea ray 300 weekender

Welcome aboard.

fuel economy and boats are usually two exclusive topics. Generally if you desire fuel economy in a 30' or greater boat, your now looking at diesels.

However in the spirit of the thread. you need to post a few things for anyone to even make a wild guess at a prop pitch change recomendations.

engine RPM's at WOT
GPS speed at WOT

your boat has a dry weight of 9500# with a wet weight probably pushing 11000#

your fuel economy while cruising will be at best 1.5 to 2 miles per gallon. your best two fuel economy speeds will be just on plane (about 16-18mph), or just above idle (about 5mph)

 

[Wingphil]

Re: Sea ray 300 weekender

I am well aware that the money pit will be thirsty. But with petrol at 3 usd a litre maximising economy makes sense.
Wot is about 4400 on specs.
As I said the boat is pretty standard, but I can not give you speed data as not had it at top speed in the water or even close.
It was bought with full intention of doing a full refit. And it's still ongoing.
I probably should have added that I am thinking of a switch to four blades from the origonal three.top speed is not an issue, well not the amount I will loose anyway.
Obviously. Whilst it is out its a good time to switch props, so any advise would be appreciated.

 

[smokeonthewater]

Re: Sea ray 300 weekender

I'd say you NEED to run it before making any decisions... I ALSO would be surprised if you see much more than 1 mpg maybe 1.5 but I doubt it my best guess 1.2 mpg if all is well

so if your prop change were to get you 10% more economy VERY unlikely IMHO you would make it all the way up to 1.32 mpg

Takes a LOOOOONG time to get back $1000 worth of props from an extra 0.12 mpg

 

[Wingphil]

Re: Sea ray 300 weekender

True enough, but the added factor that there is some damage to the installed props changes the equation slightly.
There will also be other benefits I beleive.

 

[Scott Danforth]

Re: Sea ray 300 weekender

having props repaired is part of normal maintenance.

I do not believe you will see the improvement that you think. Fuel economy and boating do not belong in the same sentence.

 

[steelespike]

Re: Sea ray 300 weekender

If it seems cost effective; have your props reconditioned for testing have it done.
As you probably know your 260s will use about 52 gallons per hour at wot.
about 1/2 that at 1/2 throttle assuming a good cruising speed.If your really intent on the very best mileage a flow meter should make it easy some can do real time gph and mileage calculations.

 

[smokeonthewater]

Re: Sea ray 300 weekender

if they are damaged then by all means fix em.. If you want fuel economy sell the boat NOW and get a trawler with about a 100 hp diesel... limit yourself to 6 mph and enjoy 6-8 mpg

 

[Wingphil]

Re: Sea ray 300 weekender

[i was hoping for a starting point, as quote for prop repair is very close to prices of some props in us.
Seems likely I will have to take a stab in the dark and then see how it reacts.
I am confused at all the comments about economy though.I am looking to have more hours at sea for less money. You guys are all spoilt by crazy cheap fuel. My fuel cost is 9 used per gallon, think on it. And think on why you don't travel everywhere at full throttle, when space permits, answer is fuel economy. Putting it another way....

Why don't you guys over there give the tax office an extra 20% of your salary in tax over the amount required by your laws. Answer we have a lot of things we liked spending it on. I am no differant I want the fun of the boat, but would like the routine chugging to open sea to be easier on the wallet, and to increase my range when it's needed. Partly so when the urge is there I can open the throttle all the way and still have fuel to get home. And partly so I am not funding the life of a liberal politician more than I have to.
One suggestion is get a small boat with small diesel, my answer is if I wanted that I would have bought that. My counter suggestion is the most economical boat is one that has wheels a chain and is pedal powered. Some call them bicycles.

 

[smokeonthewater]

Re: Sea ray 300 weekender

nobody is telling you to give up your big boat .. the boat I suggested is a style called a trawler... could be much bigger than you have and get much better mpg but the are generally slow and while you may think gas is cheap here, we don't ... remember our economy is different than yours and the fat dog gets us too in other ways.... for a starting point, I spent a few seconds with google and found this:

Prop Charts : Sea Ray Boats

I hope it's helpful