John, in the cockpit locker there are two access ports. The inboard access is for the fuel valve, the other for access to the sender.

It's easy. But remember to put the gasket back when you install the new sender. It's easy to misplace or forget...and if you do either, fuel will leak to the bilge whenever you over fill the tank.

FYI, just last evening I posted a short article in the maintenance section about the Mk II fuel tank. Go to the home page, click on Articles, and then on Maintenance.

John, I am curious about your hull number and year of manufacture. May I suggest you add that to your signature? Just click on User CP (ie, the User Control Panel) just above on the left, and then click on Edit Signature.

Larry, your article shows a plastic fuel tank, the one in our recently acquired '95 is steel. I want to pull it out and have it cleaned, probably has never been done. Just wondering if anyone has removed the tank from a C-36 Mk II and if so are there any pitfalls in what looks like a fairly straightforward task?

We did this with our 28, it was pretty simple to do, a shop locally does this work pretty cheaply and for sure it gets a clean tank, unlike fuel polishing which doesn't get gunk stuck on the walls of the tank.

Bud, you have me there. I didn't know the Mk II had anything other than a plastic tank. Your post underlines the value of providing year/hull number in your Forum signature, though.

I would imagine the removal process is straightforward. The filler hose off; the vent hose off; the sender wiring disconnected; and the valve and output hose off. Also, there must be some sort of attachment, bolted or screwed, that fastens the tank to the boat structure. These would have to be disconnected. (At the forward base of the plastic tank in one of my photos you can spot a 90 degree steel or aluminum angle that attaches the tank at the forward end. I presume there is an equivalent at the aft end.)

Good luck. Please consider capturing photos of your experience along the way, and writing a tank removal & cleaning article for our website.

John,

I had the same problem last year.

My hull number is close to yours.

I had only one access port.

I had to put in a second Beckson access port to get at the fuel sender. Get one off the Beckson web site. They have discontinued models for sale cheap.

The tank on my hull is aluminum.

The tank manufacturer is located in Utah. Their name is on the tank. I Googled them and got their telepone number. I ordered and they sent me the correct replacement. They even included a new gasket and extra screws. It's a tight fit for the replacement, but it does fit through the hole. It's nice to have the fuel gauge working again.

If you can not find the name plate on the tank, let me know and I will see if I can find my receipt. The name plate was on the top of the tank by the fuel sender.

Peter Gottgetreu
S/V SandCastle 1423

I'd recommend you get both the sender and a replacement gauge if you're doing the replacement and don't have easy access to parts in the middle of the project. If I remember correctly, the electrical resistance of the sender changes depending on the level. My gauge only read from 1/4 to 1/2, despite filling the tank and after several hours of motoring. I purchased a new sender (access port previously installed) and tested it before installing. It turned out to be the gauge was defective. Fortunately the chandlery shop was still open so I could get a replacement. At my previous marina, it would have meant putting the project of until the next trip due to distance to any parts source.

Re taking out the tank, I have a Mk II - 2002 and it has a plastic tank but, here is what I found when I just took it out. (My tank is in the port bulkhead in the aft compartment btw.)

The tank has two tabs on the forward side of the tank holding it in place with 4 screws. No problem there except that there is very little room between the forward end of the tank and the bulkhead in front of it, and there are hoses running in that space. The end result is, small hands help and you have to make very small twists of the screw driver ... but they do come out.

You obviously want to take the fuel out of the tank before you remove it and I did this with an electric oil change pump. I thought it was empty when didn't see any more pink fuel in the pump line, but when I got the tank loose, I found there was still about 1//2 a gal or more of fuel left. The tank is an odd shape and this makes it hard to reach all the spots. Just be aware of it when you take it out. It would really help to have another pair of hands to help carry it out of the cabin to keep the level of the remaining fuel even, but I did it solo with only a few splatters of fuel.

The hoses on the tank can be removed from inside the aft cabin, but you have to take the fuel sender and the output line from the tank off from the top. The output line (with the fuel shut-off) is about an 1/8th" too high to allow the tank to slide out of its spot with it still attached.

Hope this helps.

Chuck Parker

One additional comment since my last post on removing the tank.

I found that the fuel pickup tube was about 8" but the tank was about 12" deep. Floating around loose in the tank was a rubber hose about 7" long. It appears that this rubber hose attached to the pickup tube but there was no clamp and it fell off.

Without it, I was losing about 25% of my fuel tank capacity as the pickup tube was a good 3-4" from the bottom of the tank. if I ran the fuel down low (which I normally don't so) or had low fuel and rough seas, I would have started sucking in air and the engine would have shut down.

Putting this out FYI. Those on the hard may want to pull their pickup tubes and check to see exactly how far into their fuel tanks the tubes are reaching.

Chuck Parker

John...

Your point has validity of course, however, I've talked to Kent in Engineering at Catalina, and some other diesel techs, and they say the tube should be about 1/2" from the bottom of the tank, just for the reason you suggest, not 3-4"'s.

However, that does not explain the rubber tube floating around in the tank. If I attach that to the pickup tube the whole thing now extends down to the bottom and bends over,running along the bottom. I didn't mention it before, but there was also a spring in the tank that is 6" long. The only place I can figure it goes is inside the rubber tube to give it some rigidity since it doesn't fit anywhere else.

I believe the spring goes in the rubber tube, the rubber tube fits onto the plastic pickup, and the end of the rubber tube lies flat on the tube bottom.... not that that's the best place for it but that's the only way I can see it all fitting together.

I have a note out to Kent in Engineering at Catalina to see if he can confirm the actual design. I strongly feel the rubber tube fell off the pickup reducing the amount of fuel I'd be able to reach and use and wanted to warn others about this possible problem.

Chuck