fuel leaking @ filler cap???
 

My '91 1900z has developed an interesting problem. When it is hot out and the boat is in the water, fuel leaks out of the filler cap. I have the cap that is mounted on the transom about a foot above the swim step. I'm assuming that since the boat sits in the water with the stern rather low, pressure from the tank is forcing the gas back out of the cap instead of the breather tube. The breather tube is mounted on the transom and has quite a bend in it, I'm afraid to reroute the breather tube but don't know what else to do.
Hoping one of you guys has a better idea.

Re: fuel leaking @ filler cap???
 

It sounds like the breather tube may be blocked which would cause a pressure build up in the tank & force gas back up thru the filler tube.

Re: fuel leaking @ filler cap???
 

I removed the breather hose and blew it out, didn't help. If I remember correctly the outlet for the breather hose on the fuel tank is behind the inlet for the filler hose so when the tank is fairly full, they are both "submerged" and the air in the tank is at the front. Make sense?
The solution last summer was to keep the tank less than 3/4 full, but that doesn't really work for me.

Re: fuel leaking @ filler cap???
 

The breather tube is one of two options for venting the tank when fuel expands due to ambient temperature. The other is back thru the filler tube. I would ensure that the point of entry to the tank is clear & that the the thru hull fitting is also clear. Try disconnecting the line at the tank & leaving it attached at the thru hull fitting then blowing it out. Also check the fuel cap to see if it is providing a good seal. The gaskets in the fuel caps wear out over time which allows water to enter the fuel tank and/or fuel to expand back out if the breather line is blocked or not properly installed (ie kinks or sharp bends in the line). Ideally i would guess than the breather line connection at the gas tank should be near the front of the tank or at minimum somewhere ahead of the fuel connection to accomodate the normal running attitude of the boat or when its sitting on a trailer. I'm not really sure where mine is mounted. The only other option i can think of is simply not filling the tank completely to allow room for fuel expansion.

Re: fuel leaking @ filler cap???
 

Thanks for the reply, I guess I'll have to wait until it gets over 50 degrees to mess with it. It sure has been a long winter here in the NW! Thanks to the great info on this site I just received a set of smart tabs I'm going to install this week.
I had no idea there were so many proud Mariah owners out there.

Re: talari filler cap???
 

i need to replace my filler cap - looking at it from underneath i cant see a breather - it just seems connected into a rubber tube with a a bulldog clip - i am hoping i will be able to undo that if i can find a small child to get in there and just withdraw the filler cap assembly and replace - i would welcome any ideas on where to find a nice chrome replacement and the size of the filler tube - my local chandler says probably 1.5''.

Re: fuel leaking @ filler cap???
 

Try here in the "Original Mariah Parts & Vendors List".

http://www.mariahownersclub.com/foru...dors-list.html

The Indy style Filler is still available , and there are even a few on Ebay.

Re: fuel leaking @ filler cap???
 

yes i did have a look here some monhs ago - but they said the original attwood was no longer made - there are four screw holes on the one there at the moment and again that is difficult to match - thanks for the reply anyway - regards

Re: fuel leaking @ filler cap???
 

I know this is a bit of a thread revival, but do all the Mariah’s on your side of the pond vent their full tanks through the cap?
The reason I ask is my tank is vented on the port side just forward of mid ships.
If you look here it's just below where the checker starts

http://i681.photobucket.com/albums/v...fboat/vent.jpg

Re: fuel leaking @ filler cap???
 

doesn't have a vent hole - must vent from somewhere i suppose but certainly no holes on the hull.

Re: fuel leaking @ filler cap???
 

In the pic, that's the the drain for the wet-box in the port side console. Very small diameter hose and plugs easily with crud.

If I remember right, my 98 z202 vented on the port side above the swim platform. I'm trying to find a pic of the vent, but coming up empty.

Found it!
Look at button on the port side above the swim deck. That's the vent on my old boat. Not sure about the current Jubilee. I'll have to look

Re: fuel leaking @ filler cap???
 

My diablo doesn't have a wet box.
It has the double glove box but it lower one is just that.
The vent pipe loops up inside the port side consul then down to the front of the tank.
Maybe it's an EU regulation. My Sea Ray had the same setup.

Re: fuel leaking @ filler cap???
 

you just had me thinking there! :confused:
Yep definatly the tank vent, just wen't outside and sniffed it.....:rolling_head_grin:
Need to go for a lay down now.....lol

Re: fuel leaking @ filler cap???
 

ha. Nice. Better than sniffing gas fumes is a good sharpee or dry erase marker :D

So does your diablo _also_ have a a vent on the rear swim deck? Or just the one out the side of the hull?

If you look close at this pic, just forward of the cleat at the bottom of the red stripe, you can see the white drain button. Looks like it's in about the same spot as your tank vent. Was definitely the drain though, cause I had to unplug the line to it when I bought that boat.

Re: fuel leaking @ filler cap???
 

Here's a pic of my gas tank vent. See the small round black thingy on the left side of the swim deck? That's the vent.

Re: fuel leaking @ filler cap???
 

I’m starting to think they just took advantage of the existing skin fitting to bring it up to European code,
it’s the only vent I’ve got. Nothing on the transom/swim platform.

The glove box is listed as a “Cool box” in the sales brochure I’ve got.
No mention of “wet Box” and there’s defiantly no drain on it.

http://i681.photobucket.com/albums/v...309_115811.jpg

Re: fuel leaking @ filler cap???
 

Tennis ball Mikey????

Re: fuel leaking @ filler cap???
 

5 bux says the dog was driving him nuts and he put it there so the dog couldn't get to it.

If I think of it when I get home, I'll shoot a pic of the back of my jubilee. There a round knuckle (cow, pic? I don't know) sitting on the swim platform for that exact reason! :rolling_laugh:

If I'm wrong, I'll buy you a drink next time you're in Wisconsin :worry_to_laugh:

Re: fuel leaking @ filler cap???
 

Careful, I flew out to Perth Australia on the promise of a cold beer :big_chuckle:

Re: fuel leaking @ filler cap???
 

ok, so what do i get depending on who i side with? :yes_grin:

Re: fuel leaking @ filler cap???
 

Sorry Mikey, i have nothing else to offer you.
you already have a great boat and my respect......lol ;)

Re: fuel leaking @ filler cap???
 

Andy, you make it here and I'd put you up at my place. Spare room would have your name on it. You would have to promise to actually leave at some point tho. Wife might not take to kindly to you actually moving in :punch_out:

Mikey... It's just one beer, but the braging rights are worth so much more

Re: fuel leaking @ filler cap???
 

ok, truth is i was trying to get my wife to play fetch by showing her how the dog does it.....:yes_grin:

Re: fuel leaking @ filler cap???
 

mikey..........your such a bad man!! :rolling_laugh::rolling_laugh:

Re: fuel leaking @ filler cap???
 

that looks to me like the drain for your cooler, not a fuel tank vent, :)

Re: fuel leaking @ filler cap???
 

read above :D

Re: fuel leaking @ filler cap???
 

I bet he wants in on the wager over the reason for the tennis ball on the back of Mikey's boat!