Kk42 leaning and fuel transfer

[Selidster]

We're newbies so bare with us. Looking to the knowledge base of the forum. Overnight on a mooring ball the boat started leaning to starboard. Enough to make me look around. No water in the hull anywhere. Everything is as it should be, but I just put in 600 gallons of diesel, so the tanks are pretty full. No leaks. But the fuel transferred to the starboard tank as I could see from the sight glass of each tank.

Do most kk cruiser's close the valve between tanks and alternate after so many hours or pull fuel from both tanks? I'm not really sure why things changed overnight, I lifted the dingy from the port side till the fuel transferred back to equal and have closed the valve between the tanks.

Looking for insight and advice to what
1. May have caused the boat to lean?and
2. The best way to pull from the tanks?

Thanks for the continued education.
Scott

 

[Larry M]

Scott: When both of our tanks are full we list to starboard. The galley, water heater, water maker plus a few other heavy items are on that side so that’s what I’d expect. We start drawing from the starboard fuel tank and water tank to get us level. Once we are, I pull from one or the other to maintain trim. The only time the two tanks are valved together is when we are filling or transferring fuel. We do have a fuel transfer manifold/pump on Hobo which makes moving fuel easy. I was under the impression that fuel transfer pumps were standard on KK42s. If you don’t have one, maybe a PO removed it. They are simple to plumb in.

 

[dhays]

I don’t own a KK. I do know that on some boats if you leave the cross-connect line open fuel can follow a small list. So say you were both on one side of the boat creating a very small list. Fuel would travel to the low side, this can increase the list and then more fuel travels to the low side.

Many folks with singles and two tanks will draw from one tank at a time and alternate tanks to manage fuel level. This is what I do. I also have a transfer pump in the cross connect line so I can move fuel from one tank to the other.

If you don’t have a fuel transfer pump you may still be able to move fuel a different way. Most boats have a fuel manifold which allows you to chose which tank you are drawing from AND which tank to return fuel to. If your starboard tank has more fuel than your port, you can draw from the starboard tank and return fuel to the port tank while underway. This will level the tanks relatively quickly over time depending on the amount of fuel that your engines return to the tank.

Just don’t forget! If you do, you will fill up the port tank and start spilling fuel out the vent.

 

[Comodave]

What engine(s) do you have? Some engines don’t return much fuel (Lehmans) others return a lot.

 

[Selidster]

Great information. I do not have a fuel transfer pump. I'm hull #16, so a pretty early model. But all the valving is there to do what you guys have recommended. And I'll run one tank or the other and keep a close eye on things. I agree too with Hobo, all the heavy stuff seems to be starboard.

The engine is a Lehman 120. I have to say all the fuel lines. Supply and return are surprisingly small. Seem to work fine.

And the idea that the list would increase more and more also sounds right and makes sense.

Thank you all so much for your insights.

 

[hollywood8118]

Great information. I do not have a fuel transfer pump. I'm hull #16, so a pretty early model. But all the valving is there to do what you guys have recommended. And I'll run one tank or the other and keep a close eye on things. I agree too with Hobo, all the heavy stuff seems to be starboard.

The engine is a Lehman 120. I have to say all the fuel lines. Supply and return are surprisingly small. Seem to work fine.

And the idea that the list would increase more and more also sounds right and makes sense.

Thank you all so much for your insights.

Pay close attention that you dont overfill the return tank to the point it goes out the vent.
( yes it has happened to me )

HOLLYWOOD

 

[Comodave]

A Lehman 120 returns almost no fuel. Bob Smith said you could just about use a quart bottle to hold a days return. They aren’t like a Detroit that may return 30 or more gallons an hour.

 

[AusCan]

A full displacement hull will often be more susceptible to listing with an unbalanced load. The two biggest loads are water and fuel.

Keep in mind that the "equalising" valve will not level out a lean (list) when tanks already have an equal amount. Leaving the valve open will make the list worse, because the tank on the higher side will flow to the lower side until the tank levels are equal in height in a boat that is not level. The tanks volumes will not be equal.

The best way to manage the list without a transfer pump is to first fill your fuel & water tanks to a point where where the boat is level. Keep the equalising valves closed. Then just manage the water and fuel use to keep it level by alternating tank usage.

I do it with my water tanks, as they are located further from the centreline. This makes them more prone affecting the level of the boat.

 

[z1nonlyone]

I don’t own a KK. I do know that on some boats if you leave the cross-connect line open fuel can follow a small list. So say you were both on one side of the boat creating a very small list. Fuel would travel to the low side, this can increase the list and then more fuel travels to the low side.

Many folks with singles and two tanks will draw from one tank at a time and alternate tanks to manage fuel level. This is what I do. I also have a transfer pump in the cross connect line so I can move fuel from one tank to the other.

If you don’t have a fuel transfer pump you may still be able to move fuel a different way. Most boats have a fuel manifold which allows you to chose which tank you are drawing from AND which tank to return fuel to. If your starboard tank has more fuel than your port, you can draw from the starboard tank and return fuel to the port tank while underway. This will level the tanks relatively quickly over time depending on the amount of fuel that your engines return to the tank.

Just don’t forget! If you do, you will fill up the port tank and start spilling fuel out the vent.

Yes. what he said!! I have a KK39 and had the same problem..my solution was to draw from one tank and return to another. I think that with a boat with a wineglass hull shape, when you have more weight on one side, and both tanks connected, more fuel transfers to the low tank, worsening the problem! Make sure that when transfering excess fuel to the other tank that all the return valves are open on that side!! my boat had two valves, and I only opened one. Upon starting the engine, I was ready to depart when my engine died. I guess the back pressure trying to pump fuel against a closed valve was too much for the engine!!

 

[mvweebles]

Maybe go old school and retrim the boat by adding ballast to port side instead of constantly transferring fuel/water? Ballast pigs are designed to be easily bolted down, and are about $1.50/lb from a metals supplier (cheaper if you can find salvage). There may already be movable ballast on the boat somewhere (she would have been trimmed as part of commissioning). If so, you may be able to move the weights.

 

[Selidster]

Woke up to a beautiful morning in St. Augustine marina and Lemonade (my KK42) is nice and level. Thank you all for the education.
Scott

 

[catalinajack]

Fill the fuel and water tanks and balance the boat with 25 lb. bags of recycled lead shot. Find an out of the way cubby, stuff the bags in there. No need to secure. Wedged in, they will never shift.

Maybe go old school and retrim the boat by adding ballast to port side instead of constantly transferring fuel/water? Ballast pigs are designed to be easily bolted down, and are about $1.50/lb from a metals supplier (cheaper if you can find salvage). There may already be movable ballast on the boat somewhere (she would have been trimmed as part of commissioning). If so, you may be able to move the weights.

 

[Comodave]

We had a trim issue on a previous boat. Bought a bunch of lead ingots, think they were around 60ish pounds each. Laid them in the boat and when we got it trimmed the way we wanted and then glassed over them to hold them in place.

 

[catalinajack]

We had a trim issue on a previous boat. Bought a bunch of lead ingots, think they were around 60ish pounds each. Laid them in the boat and when we got it trimmed the way we wanted and then glassed over them to hold them in place.

The problem with glassing the lead in permanently is that later changes may again put the boat out of balance. Lead shot in bags doesn't move and is portable.

 

[Comodave]

That boat had a permanent list so I wanted to permanently fix it.

 

[OldDan1943]

There is a fine line on where to put the ballast.
Up high, it may have an effect on roll recovery.
Low in the hull aka the bilge, little or no effect.
Gotta find the sweet spot.
I used shot gun pellets in the cloth bags to level my N46. Disadvantage to using bags is, eventually the bags will deteriorate and then, we/you/me will be using the wet vac to suck up all the free pellets.

 

[rslifkin]

Instead of fiberglassing the ballast in place, what about making a fiberglass box attached to the hull to contain the ballast? Then it's still held in place and contained, but can be moved in the future if necessary.

 

[Comodave]

I like to have it firmly affixed so it doesn’t move. It is unlikely that the trim will change significantly in the future. And if it does, fiberglass can be cut or ground out. That is the beauty of fiberglass, you can always change it. And below in the bilge you don’t have to finish it to an extreme degree.

 

[Sailor of Fortune]

Woke up to a beautiful morning in St. Augustine marina and Lemonade (my KK42) is nice and level. Thank you all for the education.
Scott

Everyday in St Augustine is nice!

 

[OldDan1943]

Instead of fiberglassing the ballast in place, what about making a fiberglass box attached to the hull to contain the ballast? Then it's still held in place and contained, but can be moved in the future if necessary.

I like the idea of fiberglass boxes (with thumb screw tops). Keeps the ballast in place but allows for 'fine adjustment' if necessary.

 

[mvweebles]

My Willard 36 has a few of these pigs beneath the side decks. The "ears" have metal straps holding them down so easily moved if something changes in trim.

https://www.rotometals.com/whole-lead-pig-ingot-58-62-pounds-99-9/

 

[Ventana]

Scott,
I know you posted this a while back, but the issue just came up again for us. Our KK42 seemed to do pretty well staying level, but lately I was noticing the list was getting worse as we emptied one water tank and switched to the other. Seems at some point I must have opened the valve connecting the two fuel tanks. The boat leans a very little bit with one water tank full and one empty, but the real difference was when the fuel tanks were allowed to gravity transfer. I closed the crossover valve on the fuel tanks, refilled the water tanks, and now even with one water tank empty the boat stays relatively level. Longer cruising where we would use the watermaker the tanks would remain almost full, but shorter cruises like we are doing now I don’t want to un-pickle the watermaker.

We're newbies so bare with us. Looking to the knowledge base of the forum. Overnight on a mooring ball the boat started leaning to starboard. Enough to make me look around. No water in the hull anywhere. Everything is as it should be, but I just put in 600 gallons of diesel, so the tanks are pretty full. No leaks. But the fuel transferred to the starboard tank as I could see from the sight glass of each tank.

Do most kk cruiser's close the valve between tanks and alternate after so many hours or pull fuel from both tanks? I'm not really sure why things changed overnight, I lifted the dingy from the port side till the fuel transferred back to equal and have closed the valve between the tanks.

Looking for insight and advice to what
1. May have caused the boat to lean?and
2. The best way to pull from the tanks?

Thanks for the continued education.
Scott