Burn Rate

[lazy grady]

I have a 24' Walk Around Cabin, Hard Top, Explorer Model GW that is a 1992 Model Year. It has been refurbished completely and up fitted for cruising that is estimated to add another 750 pounds of weight. It is powered by a 2009 Yamaha F-250 four stroke outboard with only 600 hours on it. I need a "source" to determine the "burn rate", say in gallons per hour at cruising speed; say 20 mph?

 

[big_tuna]

You can buy a NMEA2000 yamaha data cable which will connect your motor and fish finder to give you exact burn rates to calculate your mpg

 

[DennisG01]

Did the Yamaha come with a Yamaha multi-function gauge? That may already be equipped with that function.

 

[Doc Stressor]

Yep, that's how to do it. Older technologies like Flowscan are obsolete and less accurate.

 

[Hookup1]

What kind of chart plotter do you have?

Based on your previous posts on distances in the Bahamas I'm assuming you are trying to figure out if you have enough fuel to get there. Just a little advice for you about this trip - do what you want with it. Crossing the gulf stream in a small boat to another country with no experience on the Bahama bank is a pretty risky thing to do. You are really on your own crossing the stream and over there. I would recommend doing a trip like this during a calmer part of the year and "buddy up" with another boat to make the trip. Try posting in the Gulfstream Grady Group. In the past they arranged flotillas - not sure if they still do - but maybe you could find others.

I haven't been back to the Bahamas in a long time. Every time I went they were the coolest trips my family and I ever did. Plan carefully and stay safe.

 

[family affair]

I'm not sure if you are asking what to expect or how to get the data.?
If what to expect, the boat is barely planing at 20. Typically better fuel burns are had around 25-30 with most GW hulls properly set up. From memory I would say around 1.5 mpg at 20 or 12-14 gph.

 

[lazy grady]

I'm not sure if you are asking what to expect or how to get the data.?
If what to expect, the boat is barely planing at 20. Typically better fuel burns are had around 25-30 with most GW hulls properly set up. From memory I would say around 1.5 mpg at 20 or 12-14 gph.

3/24/22 Thanks for the response. My boat is away for preparation to make the crossing. Your estimates are helpful in that I am trying to do some tentative routing considering the need for carrying extra fuel as well as where to fuel up. Given the added weight to my boat (hard top and custom work done for overnight cruising) say 750 pounds, I am thinking 15 gallons per hour burn rate and say 23 mph cruising speed?

Your thoughts?

 

[family affair]

If the boat is properly set up, I'd say 15 gph is on the high side giving you a conservative range as long as you aren't punching through tight 4+ footers with 20+ mph wind on the nose.
Our Islander with twin f150's at that speed only drinks around 11-13 gph.
All of this depends on the right prop. Without that, throw everything I said out the window.

 

[DennisG01]

My boat is similar, with 250HP... but it's a 2-stroke. But for a "guide"... I'm at 10 - 13 GPH running in the mid to upper 20-mph range. At 3,700/3,800 RPM I'm hovering in the upper 9gph to low 10gph range.

But... what about my question?

 

[blindmullet]

That's with a 300zuke on an Explorer without a Hardtop.

 

[SeanC]

2006 F250, 2006 Seafarer, hardtop, enclosure, botton paint, 92 gal fuel, 2-3 people, cruise about 22-24mph, reasonable conditions I get about 2.3 mpg.

 

[white diamond]

View attachment 25091
That's with a 300zuke on an Explorer without a Hardtop.

Blindmullet, I also have a Explorer 246G with a 300 Zuke. I am running the old style Suzuki 16x17 prop the dealer put on the motor and feel that I could do better. What prop are you running?

 

[blindmullet]

Blindmullet, I also have a Explorer 246G with a 300 Zuke. I am running the old style Suzuki 16x17 prop the dealer put on the motor and feel that I could do better. What prop are you running?

I have the newer style 20p. You actually have the best pitch for that setup. I can't get the last 400-500 RPM.