Fuel economy

[Finbreaker]

Greetings all! I have a 2008 2320SL powered with a Yamaha 250 outboard. The motor has 575 hours on it, and I bought the boat used. I am only getting like 1.8 mpg fuel economy and was wondering if other 2320SL owners are noticing similar numbers. I even swapped out the prop for a new 4 blade stainless prop with the proper calculated pitch. Any thoughts or recommendations? Thanks!

 

[Brent]

The rule of thumb is set motor height with boat on plane and loaded heavy. The anti ventilation plate should be skimming the water surface. Next prop to max rpms. Info from Prop Gods. Other factors like trim tabs and real Permatrim will help. What is your motor mounting hole with top holes is #1 ? What is the max motor rpm? Which prop installed! Specs? Ss or AL? 3 or 4 blades?

 

[Brent]

The rule of thumb is set motor height with boat on plane and loaded heavy. The anti ventilation plate should be skimming the water surface. Next prop to max rpms. Info from Prop Gods. Other factors like trim tabs and real Permatrim will help. What is your motor mounting hole with top holes is #1 ? What is the max motor rpm? Which prop installed! Specs? Ss or AL? 3 or 4 blades?

For optimal fuel and motor efficiency

 

[Billman]

I have a 2016 2320 with Yamaha 250 (4.2L), I'm seeing cruise numbers in the range of 2.8-3.0 mpg with nearly full fuel and three adults. Honestly, I'm not sure about the prop, will share details this weekend.

 

[Swatski]

Greetings all! I have a 2008 2320SL powered with a Yamaha 250 outboard. The motor has 575 hours on it, and I bought the boat used. I am only getting like 1.8 mpg fuel economy and was wondering if other 2320SL owners are noticing similar numbers. I even swapped out the prop for a new 4 blade stainless prop with the proper calculated pitch. Any thoughts or recommendations? Thanks!

What are you reading your speed off of? If it's a pitot, it could be off, as compared to GPS, some deviation is okay (speed over land vs water), but a large difference could skew your mpg numbers.

 

[Finbreaker]

The rule of thumb is set motor height with boat on plane and loaded heavy. The anti ventilation plate should be skimming the water surface. Next prop to max rpms. Info from Prop Gods. Other factors like trim tabs and real Permatrim will help. What is your motor mounting hole with top holes is #1 ? What is the max motor rpm? Which prop installed! Specs? Ss or AL? 3 or 4 blades?

 

[Finbreaker]

Hey Brent, our motor is mounted to the Armstrong bracket out back, we have a new 4 blade stainless steel prop. We do have trim tabs as well. Lemcos I believe. We are running usually against ocean swell but even when we are on a dead flat calm surface in the Lee of the islands our fuel economy never goes above 1.9-2.0mpg. We are getting about 23-25 mph at 5000 rpm and nothing really seems to change the fuel economy. Our bilge is always completely dry, but the boat just seems sluggish running on plane. Just trying to see if I’m missing something obvious before I start wondering if the wood core of the boat is waterlogged or something..

 

[Brent]

What is your max WOT rpms.?

 

[Finbreaker]

What is your max WOT rpms.?

About 5800-6000rpms...

 

[A-K]

About 5800-6000rpms...

Those RPMs seem good.
Are you gathering your MPH from another source other than a GPS?

 

[Finbreaker]

Those RPMs seem good.
Are you gathering your MPH from another source other than a GPS?

I use both the GPS and the engine gauge and get pretty close to the same reading on both. Our max speed is about 30mph. But switching from a smaller, older 3 blade prop to a bigger 4 blade stainless steel prop did nothing for our fuel economy. It’s always 1.8-2mpg at the most. And this is with just 2 guys on board. Doesn’t matter if the fuel tank is full or empty. Always the same mpg.. puzzling...

 

[blubby07]

I have the same boat and motor and that’s all I get on a good day but I run really heavy w tuna tower large kill bag w ice on the swim step coolers full and gear w 4 fat guys.
getting out of the hole takes time it stinks I wish I had a300

 

[JPKEMTP]

Hey Brent, our motor is mounted to the Armstrong bracket out back, we have a new 4 blade stainless steel prop. We do have trim tabs as well. Lemcos I believe. We are running usually against ocean swell but even when we are on a dead flat calm surface in the Lee of the islands our fuel economy never goes above 1.9-2.0mpg. We are getting about 23-25 mph at 5000 rpm and nothing really seems to change the fuel economy. Our bilge is always completely dry, but the boat just seems sluggish running on plane. Just trying to see if I’m missing something obvious before I start wondering if the wood core of the boat is waterlogged or something..

Is there any chance you are holding water in the Armstrong racket?
JP

 

[big_tuna]

I don't have tons of experience but I wouldn't expect a 4 blade prop to immediately give you an increase in mpg at cruising speed. It will give you more torque at lower RPMs allowing for more lift thus quicker times to plane as well a lower planing speed. Also, your low speed maneuverability probably improved.

You haven't told us which bolt holes your motor is mounted at...

I can't imagine filling the armstrong bracket with water would make a large enough impact. That's maybe 10 gallons?

I've got a 2310 with a 4 blade prop, permatrim, wide trim tabs, 150 gallon gas tank, 50 gallon bait tank. I get about 1.7-2.2mpg depending on load. So I would say your mileage is not too far off. But I need to raise my motor... Will try that this winter...

 

[Finbreaker]

I don't have tons of experience but I wouldn't expect a 4 blade prop to immediately give you an increase in mpg at cruising speed. It will give you more torque at lower RPMs allowing for more lift thus quicker times to plane as well a lower planing speed. Also, your low speed maneuverability probably improved.

You haven't told us which bolt holes your motor is mounted at...

I can't imagine filling the armstrong bracket with water would make a large enough impact. That's maybe 10 gallons?

I've got a 2310 with a 4 blade prop, permatrim, wide trim tabs, 150 gallon gas tank, 50 gallon bait tank. I get about 1.7-2.2mpg depending on load. So I would say your mileage is not too far off. But I need to raise my motor... Will try that this winter...

That all makes good sense. Thanks for all the advice.. Parker boats are on the heavier end for boats of that length. I don’t know which holes our motor is mounted to on the Armstrong bracket but I’ll check. I just was trying to figure out if our core was waterlogged or there was some other obvious thing I was overlooking that would kill our fuel econ. It’s almost impossible to run with the motor trimmed all the way up here in Southern California because of our constant and variable swells. So I’m running bow down most of the time.

 

[big_tuna]

That all makes good sense. Thanks for all the advice.. Parker boats are on the heavier end for boats of that length. I don’t know which holes our motor is mounted to on the Armstrong bracket but I’ll check. I just was trying to figure out if our core was waterlogged or there was some other obvious thing I was overlooking that would kill our fuel econ. It’s almost impossible to run with the motor trimmed all the way up here in Southern California because of our constant and variable swells. So I’m running bow down most of the time.

ahh I am in socal as well! YOu will notice people from different areas will seemingly post better mpg performance as they don't have to deal with our socal chop nor are loaded down with a 50-60 gallon bait tank. Funny you are talking about MPGs, are you considering the run out to tanner bank? I am planning my trips now. I'm going to bring some VP racing 5 gallon jugs just in case.

 

[Brent]

Greetings all! I have a 2008 2320SL powered with a Yamaha 250 outboard. The motor has 575 hours on it, and I bought the boat used. I am only getting like 1.8 mpg fuel economy and was wondering if other 2320SL owners are noticing similar numbers. I even swapped out the prop for a new 4 blade stainless prop with the proper calculated pitch. Any thoughts or recommendations? Thanks!

what is your standard load? Full gas? Full crew and food for them. Bait tank ? Grand piano?lol

 

[Finbreaker]

what is your standard load? Full gas? Full crew and food for them. Bait tank ? Grand piano?lol

Usually run the boat with just 2 guys. Big open deck- we have no bait well. 135 gallons of gas. No tuna tower, no extra fuel tanks. Just bizarre to get less than 2mpg

 

[Finbreaker]

ahh I am in socal as well! YOu will notice people from different areas will seemingly post better mpg performance as they don't have to deal with our socal chop nor are loaded down with a 50-60 gallon bait tank. Funny you are talking about MPGs, are you considering the run out to tanner bank? I am planning my trips now. I'm going to bring some VP racing 5 gallon jugs just in case.

Ha ha yes Tanner Bank has been going off. My next door neighbor is a commercial fisherman and has been getting some big BFs out there. Might think about getting out there myself!

 

[A-K]

My 2320 loaded heavy, including 50 gallon bait tank will get 1.6 to 1.8 in the ocean. I run fast and only fish the ocean so I only have ocean fuel economy numbers.

When the seas kick up fuel economy diminishes.

If your worried about water logged transom or foam I would suggest.

Reaching your hand in the bilge and physically touching the foam to see if it’s wet. If it’s wet just put a little fan over your bilge and let the air draw out with all pie plates off (move air through bilge). If it’s still wet after 1 or 2 days it’s might be water logged.

For the transom you could just tap on it something that won’t chip the gel coat. If it sounds dead (low thud vs high crisp sounding tap) it could be water logged.
Or drill a small hole and see if the wood is dry then fill with epoxy.

Good luck.