`keel vs aft fuel tank

[Jedymar]

Hi guys, in our 53 convertible we have 3 fuel tanks. We know the forward fuel tank is used for the generator. We like to know which fuel tank is better to use for the main engines as day tank aft vs mid tank. glad to here what you guys think.

thanks

Jediael

[rsmith]

Just fyi on my boat advertised capacity is 450 forward 350 mid 250 aft I’ve run some long range runs where I needed to make sure I used all the fuel out of the tanks be I switched I’ve found the usable fuel was much less than the advertised and this was run until the engine lost power. I found you can pull the boat off plane and if your quick change tanks without the engine dying. The actual usable fuel is 435 303 and 224. Also I have graduated dip sticks for the forward and mid tanks. Aft is under the back deck and can’t access it. The gauges on all these boats are a joke. If you really need to know how much fuel you have onboard you need to stick the tanks. I’ve got a chart I’ll post when I go down to the boat that should be close to yours but I’d suggest you verify it.
As far as using tanks I usually run the forward and mid. I never ever run both engines off the same tank it’s just bad practice. One thing I’ve found that really kills the speed is the water tank it’s all the way fwd and 275 gallons I never carry more than 50 gallons in it that’s more than enough for a day fishing trip.

[Dragonten]

My 53 only has two fuel tanks. Both are in the middle of the boat. I always run each engine off of its own tank. Would not recommend running together unless needed for some reason. The generator I believe runs of the forward tank.

[rsmith]

My 53 only has two fuel tanks. Both are in the middle of the boat. I always run each engine off of its own tank. Would not recommend running together unless needed for some reason. The generator I believe runs of the forward tank.

The convertible is a completely different fuel and water tankage system from the motor yachts

[bostonhatteras]

Just fyi on my boat advertised capacity is 450 forward 350 mid 250 aft I’ve run some long range runs where I needed to make sure I used all the fuel out of the tanks be I switched I’ve found the usable fuel was much less than the advertised and this was run until the engine lost power. I found you can pull the boat off plane and if your quick change tanks without the engine dying. The actual usable fuel is 435 303 and 224. Also I have graduated dip sticks for the forward and mid tanks. Aft is under the back deck and can’t access it. The gauges on all these boats are a joke. If you really need to know how much fuel you have onboard you need to stick the tanks. I’ve got a chart I’ll post when I go down to the boat that should be close to yours but I’d suggest you verify it.
As far as using tanks I usually run the forward and mid. I never ever run both engines off the same tank it’s just bad practice. One thing I’ve found that really kills the speed is the water tank it’s all the way fwd and 275 gallons I never carry more than 50 gallons in it that’s more than enough for a day fishing trip.

I found out the 'run out of fuel getting off plane' phenomena entering Beverly Ma harbor where the no wake barrier is about 500 ft from the beach. I never pulled out the cabin step and accessed the fuel valves faster than that day and yes it didn't actually run dry but was sputteringly close.

[Steve Mannshardt]

Hi guys, in our 53 convertible we have 3 fuel tanks. We know the forward fuel tank is used for the generator. We like to know which fuel tank is better to use for the main engines as day tank aft vs mid tank. glad to here what you guys think.

thanks

Jediael

I have a 53’YF. Centerline tanks in the keel with genset supplied from the fwd tank. Third tank is in the lazarette running crosswise. I typically run from the centerline tanks and treat the laz tank as ballast. Using the laz tank fuel has an effect on overall fore/aft trim

[Cricket]

As Scott previously said the tanks in our old old 50c's are basically the same setup as the 53c.
We usually leave 1 engine on the front tank all the time and then run the other on the aft tank on the way out and while trolling and then switch that engine to the mid tank for the ride home.
Like Scott we've had ours for a long time so we have a very accurate fuel burn chart for reference.

We also added a fuel polishing system that has its set own of pickups and returns so we can easily transfer fuel to other tanks if we really need it, much more control than using the engine returns.

[Jedymar]

Thank you guys

[Nube]

Good evening all,

I realize that this post is a bit dated, but curious as to why you wouldn't want to run both engines off of one tank.

[Captain Ralph]

Good evening all,

I realize that this post is a bit dated, but curious as to why you wouldn't want to run both engines off of one tank.

If one tank has a problem (water, debris, murphy), the other tank may be clear and not disable the whole boats operation.
Boat trim can be maintained while motoring and at dock side.
When Bunkering, you can determine if one engine is consuming more than the other (less gen-set).
Fuel filter inspection can help determine if one tank is developing issues.

May be more ideas based on two engines, two tanks, two different fuel draws.

But not all practice this. Some SFs draw from only one tank or the other to lighten up the forward or aft tank first quickly. Wanting that correct bow angle and wake while fishing AND that home/trophy run to the scales that requires max trim & speed.

It is really up the the boat, use and what the owner wants.

I always take on island fuel in one tank, both engines run from separate tanks from then on.