Kk42 fuel tank sight glass graduations

I have long suspected mine are off. Have not taken the chance to correct when filling due to time constraints at fuel dock etc. If you have a 42 with confirmed sight glass measurements, I would like to know what they are. Mine has the fiberglass tanks, but assume the steel tanks are close enough.

Please include references for the measurements, ie: from tank top or bottom vs. sight glass top r bottom, and perhaps sight glass heights vs. tank heights.

This has become an issue as I originally planned on taking fuel on in Cartagena and now will most likely not. I have approximately a 140ish hr run to P.R. and am thinking about fuel.

Thanks

My boat is different than yours, so there is no point in giving you my tank dimensions. But you should be able to calculate the capacity of your tanks by measuring their size. One cubic foot equals 7.47 US gallons.

Rossland,

Unfortunately the tank has alot of curvature and odd shape. So any calculations would still be a guess.

Fuel Tank sight glass gallons markings.

Scott,

The KK 42 tank is sort of a fat upside down right triangle with the curve of the hull for the hypotenuse for one side, plus they are tapered.

Only reliable way would be when they are empty, to put in 50 Gal at a time for each side tank, Being sure the boat is level, then record the corresponding inches in the sight glass.

You know 350 gallons is total tank size according to the manufacturer. I can't say how accurate that is. I can tell you it is not linear, but next time you fuel up, take the time & see what you can do with making a graph.

Richard Bost may have that all graphed out, but he is in Viet Nam for a couple months. Any other KK 42 owners have something on this ?

Do the Kadey-Krogen guys in Stuart, Florida have anything ?
Can some one call them & ask ?

Any other owners that have done the home work on this & graphed this out, are you willing to share with us ?

it would be appreciated by all of us KK42 owners.

Thanks.

Alfa Mike

Please, everyone, step back from the ledge.
Sight Tubes are are not rocket science and work because of their simplicity.
But from one boat to the next, if you want accurate readings, you must calibrate them yourself.

Here are mine. I will be glad to email the spreadsheet to anyone who emails me.

I'm sure these would be accurate for any KK42 with original tanks plus or minus 50 gallons and probably less, because the space is only so much.

Fuel chart -- KK 42

Richard my Friend.

Thank you.

This will help out Scott a lot.

Hay Scott - hope this helps you.

Alfa Mike

I received Richard's tank info to confirm my thoughts before we left Cartagena. It is why I ultimately decided not to refuel there. Because of the current and even slower then predicted average speed, I did reduce RPM a bit to save fuel(Richard's chart also handy). Came in to Ponce w/ 40 gallons left. So probably could have maintained normal RPM, but don't like to cut it so close in such rough seas.

Thanks for the help

Worked out great

I love it when a plan comes together !

Scott, glad we could help.

TF guys always happy to help.

Alfa Mike

Sealife said:

I received Richard's tank info to confirm my thoughts before we left Cartagena. It is why I ultimately decided not to refuel there. Because of the current and even slower then predicted average speed, I did reduce RPM a bit to save fuel(Richard's chart also handy). Came in to Ponce w/ 40 gallons left. So probably could have maintained normal RPM, but don't like to cut it so close in such rough seas.

Thanks for the help

Click to expand...

Good job Scott.

I got into Colon with about 10 to 20 gallons. The fact that I'm unsure is a bit irritating.
In hindsight, I should have been recording the numbers while refueling and then average.
I can go back to the old logs and do so.
I suppose I will sooner or later.

Richard, I used the return line sight glass valve open trick we discussed to help. After thinking about it for a time. I don't think we could really "suck" air into the line in a rough sea. 1-2gph is such a small amount of flow, my fuel filters (lower then tanks) are basically gravity fed. So if supply line from tank momentarily was exposed to air, when the fuel sloshed back I think it would burp itself. Just some thoughts.....