Auxiliary fuel Tank

My tank is on my stern at topside underneath live well. I have read you have to have this tank higher than gastank portal. did You have to do that? I want to use 1 of these tanks but am hesitant cuz I’d have to lift up onto live well and that would get old real fast.
These Scepter gas caddy tanks have a pump handle you can manually pump, but that can also be tedious. What I did was modify the air vent with a Shrader valve stem so it can be pressurized with a bicycle or 12v pump. This allows you to drain the auxiliary tank without having to manually pump the handle or raise it higher than your main tank.

If you use a DeWalt "Max Inflator" or similar battery powered air inflator pump, it makes quick work of draining these aux tanks. The nice thing about this DeWalt, is it has a digital pressure readout and auto-shutoff so you can set the correct pressure and it won't over-inflate the tank. So it's easy to keep the right pressure.

This is one of the videos that explains how to modify it with the valve stem, along with replacing the wheels, which was also very helpful.

 
55 gallons extra onboard with a enclosed electric pump
Comes in handy in the Lake of the Ozarks early & late season when only a handful of gas docks are open on limited hours and for night cruising
 
Now forgot to add we can cover more area faster as have much greater range @ higher speeds
 
Also you can see have the Sharrow prop on the Yamaha 350 with the stern thruster & have the Sideshift front thruster also
I was about to say that looks like a Sharrow prop...

I think you are the first I've seen with an actual install.

Care to share some thoughts on before/after? I'm close to pulling the trigger, but it's a lot of coin to drop without any real world experience reviews...
 
55 gallons extra onboard with a enclosed electric pump
Comes in handy in the Lake of the Ozarks early & late season when only a handful of gas docks are open on limited hours and for night cruising
Full, that is over 500lbs. You just dump 5/6 gallon cans into that? Otherwise you need really strong friends or a forklift. I eventually want one but i don't need one yet. When I retire, i need one (5-7 years)
 
You have all the Bell's and Whistles! I am sure the group would be very interested in any specs you can provide on speed vs RPM using that prop, and thoughts on the thruster system after a summer of use - I see your older post on that topic concluded the thrusters were awesome! Nice Setup!
 
I was about to say that looks like a Sharrow prop...

I think you are the first I've seen with an actual install.

Care to share some thoughts on before/after? I'm close to pulling the trigger, but it's a lot of coin to drop without any real world experience reviews...

What prop are you running now? Likely that you can change it to something else to that closely matches what a Sharrow would do AND pocket $4000 in gas money in the process. If you include potential repairs from prop strikes with wood or bottom you may never hit that payback period.
 
What prop are you running now? Likely that you can change it to something else to that closely matches what a Sharrow would do AND pocket $4000 in gas money in the process. If you include potential repairs from prop strikes with wood or bottom you may never hit that payback period.

What prop are you running now? Likely that you can change it to something else to that closely matches what a Sharrow would do AND pocket $4000 in gas money in the process. If you include potential repairs from prop strikes with wood or bottom you may never hit that payback period.

not to totally hijack the thread, I posted last summer when the boat was new... I think I'm dialed in pretty well, and propgods basically said the same last year. I could get a bit better low end likely and give up some top end, but it was more of a preference thing...

From my old thread:
...the motor is a Yamaha VMax SHO (250). Delivered with a 15T x 15.75 Saltwater Series II prop (pretty sure that 15 pitch?). Prop seems fine overall. Boat is a L series 24 foot with the SPS + toon setup. With 2 adults and 2 teens (~500lbs), and 15 gal of fuel onboard, and bimini deployed, we were topping out around 42-44 mph (Garmin indicated). RPM's right around 6k, but not above.​
 
Yeah that a decent setup for sure. If you switch to a Sharrow:

1) make sure you datalog your current fuel burn at 500rpm increments
2) can return the Sharrow for a refund
3) consider a different prop first - Enertia's are very good and you could even try a 16p SWS2
4) raise engine mounting height

Based on your mostly-no wake lake I don't see how a $5K prop could ever be justified at least financially. Maybe if running offshore A LOT then the fractional gains at cruise start adding up and might make sense.
 
Yeah that a decent setup for sure. If you switch to a Sharrow:

1) make sure you datalog your current fuel burn at 500rpm increments
2) can return the Sharrow for a refund
3) consider a different prop first - Enertia's are very good and you could even try a 16p SWS2
4) raise engine mounting height

Based on your mostly-no wake lake I don't see how a $5K prop could ever be justified at least financially. Maybe if running offshore A LOT then the fractional gains at cruise start adding up and might make sense.

Agreed with all points…. It’s a “want” and not a need….

That said, if it’s more efficient at no wake speed it will take forever to pay for itself, but will payoff in quietness…. Not that things are loud, but if I can shave 100rpm and get the same speed, it would be even quieter to cruise. And if the reverse operation is as much better as they say, it would help a lot docking and maneuvering, though a side thruster migh make more sense. But another thing to train the family how to use, lol. I just count my blessings when they remember to tilt the motor into the water before they start it. :p
 
These Scepter gas caddy tanks have a pump handle you can manually pump, but that can also be tedious. What I did was modify the air vent with a Shrader valve stem so it can be pressurized with a bicycle or 12v pump. This allows you to drain the auxiliary tank without having to manually pump the handle or raise it higher than your main tank.

If you use a DeWalt "Max Inflator" or similar battery powered air inflator pump, it makes quick work of draining these aux tanks. The nice thing about this DeWalt, is it has a digital pressure readout and auto-shutoff so you can set the correct pressure and it won't over-inflate the tank. So it's easy to keep the right pressure.

This is one of the videos that explains how to modify it with the valve stem, along with replacing the wheels, which was also very helpful.

Thanks for sharing! I’ve got the same setup and will likely change out the tires and maybe do the valve stem.
 
Agreed with all points…. It’s a “want” and not a need….

That said, if it’s more efficient at no wake speed it will take forever to pay for itself, but will payoff in quietness…. Not that things are loud, but if I can shave 100rpm and get the same speed, it would be even quieter to cruise. And if the reverse operation is as much better as they say, it would help a lot docking and maneuvering, though a side thruster migh make more sense. But another thing to train the family how to use, lol. I just count my blessings when they remember to tilt the motor into the water before they start it. :p


Most of the noise I hear at low speeds - at least on my boat - is vibration coming from the engine itself that then rattles the gates. Pretty annoying but I could quiet it down with some 3M product. Others may be hearing prop chatter which could be a hub issue.

The Sharrow might be able to reduce a few db's but for the money I'd probably just buy an upgraded sound system and turn it up! In all seriousness I'd be careful about the claims Sharrow is making, neat product but there's a reason why very few are swinging one.
 
Most of the noise I hear at low speeds - at least on my boat - is vibration coming from the engine itself that then rattles the gates. Pretty annoying but I could quiet it down with some 3M product. Others may be hearing prop chatter which could be a hub issue.

The Sharrow might be able to reduce a few db's but for the money I'd probably just buy an upgraded sound system and turn it up! In all seriousness I'd be careful about the claims Sharrow is making, neat product but there's a reason why very few are swinging one.

Totally agreed on all counts. That said, based on my obsession with drones (not that i can fly one, lol). There's some real benefits.

What's unclear is whether it translates to anything measurable in real world boating. BoatTest is great, but not exactly independent/scientific... Not that getting good scientific results are easy in boating due to wind/current/waves/etc...

honestly, if it was $1-2k, i'd be more willing to take a chance... $5k is too much. I get why its that much, the production is very expensive.

I will keep sitting on the sidelines for now, lol...
 
BoatTest's constant pushing of the Sharrow comparisons is definitely suspect - clearly these are paid adverts at this point, and some of the results are being picked apart by some eagle-eyed boaters on some other forums. The biggest issue being Sharrows - which admittedly have more blade area and have lower slip numbers - aren't being compared to other props that are designed for efficiency. Specifically Mercury made the ECO Enertia to be extremely efficient for larger and high-drag boats, but BoatTest continues to avoid this comparison.

Which just further hammers home the point that not all props are created equal - some are made for speed, some for efficiency, some to get lower-torque engines up to their optimal WOT RPM, etc. etc. Sharrows seem to play in that larger, heavier category (think offshore express boats) that rack up thousands of hours that can take advantage of those cruising speed fuel savings. But for the typical rec boater looking for decent performance at a reasonable initial and life-cycle cost the Sharrow just is going to have a very hard case to make.

And yes if they can cut the cost in half, keep the WOT speed and cut fuel consumption by 10% I'd probably be interested as well! Maybe in a few years if they can start selling them at scale.
 
BoatTest's constant pushing of the Sharrow comparisons is definitely suspect - clearly these are paid adverts at this point, and some of the results are being picked apart by some eagle-eyed boaters on some other forums. The biggest issue being Sharrows - which admittedly have more blade area and have lower slip numbers - aren't being compared to other props that are designed for efficiency. Specifically Mercury made the ECO Enertia to be extremely efficient for larger and high-drag boats, but BoatTest continues to avoid this comparison.

Which just further hammers home the point that not all props are created equal - some are made for speed, some for efficiency, some to get lower-torque engines up to their optimal WOT RPM, etc. etc. Sharrows seem to play in that larger, heavier category (think offshore express boats) that rack up thousands of hours that can take advantage of those cruising speed fuel savings. But for the typical rec boater looking for decent performance at a reasonable initial and life-cycle cost the Sharrow just is going to have a very hard case to make.

And yes if they can cut the cost in half, keep the WOT speed and cut fuel consumption by 10% I'd probably be interested as well! Maybe in a few years if they can start selling them at scale.

It's like you picked my brain, lol!

Part of your discussion brings me back to my thoughts to switch to a 4 blade prop... low speed cruise, and mid speed watersports as my only usage makes me wonder if it would be more efficient...

but, honestly, I'll be on the hook with a beer in hand in a month and probably not thinking about it again till October... :D
 
Well I’m a impulsive carefree footloose type. When I do a setup it’s for convenience. Only questionable upgrade is prop. But wanted the low speed maneuverability and more reverse. Plus top end
 
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