handfulz28

1991 carb'd Mark IV 454 MAGs, all stock. Replaced a fuel pump and pump-to-carb metal line today and it's leaking at the carb inlet. I have to admit I didn't use the Merc hard line but had to get a pre-flared and fitting'd brake line from the auto store and found a guy to bend it.
I thought if anything, I'd screw it up down by the pump where it's hard to see, but "lucky" for me it's right on top. I didn't use any thread tape/seal as I understood it wasn't needed. I ended up cranking the fitting as tight as it would go and it still leaked.
When I was removing the old line, the large fitting on the carb came loose so I removed that and found out there's a filter and spring in there. I replaced the filter and put that back together with seemingly no issues.
At this point I'm ready to go with adapters and AN fittings. Something along these lines: http://store.wpsracing.com/aercarandfue.html
I'd appreciate any help figuring out what size that large inlet is on my carb. There's also a -6 to 3/8" inverted flare adapter that might work.
I've read the threads on USCG approval and what's required is just Type A1 hose. But at this point I might just use the blue socketless stuff, maybe put a fire sleeve over it.
All input is appreciated.
Thanks,
Michael

handfulz28

I wonder if I mixed a 37 degree with a 45 degree flare? How would I know, other than the leak?

cuda

I went throught the same troubles when I swapped out engines in boat. I couldn't use the original fuel line because this engine has closed cooling. I tried bending steel lines myself, but as you can see from the pictures, I had to turn a 90. I finally went to a speed shop and had them make up a fuel line with all the fittings I needed.

The last picture showed how much I enjoyed working around that damn closed cooling in that bilge.

handfulz28

Hey Cuda, do you remember which fittings they used? It looks like I'm going to do what you did, just trying to work out which fitting at the carb. Either a -6 to inverted flare, or replace the whole carb fitting with -6 to 7/8"-20 (if that's the right one) adapter.
It looks like the pump side will get an NPT to -6, then a -6 150 degree to run the hose around the side of the pump and around and up to the carb.
I was really hoping to get out this weekend.
Thanks,
Michael

cuda

Just take the parts with you. Show him what you need on both ends, and how long it needs to be, then let him have at it. I'm pretty sure the a/n fittings were -6.

handfulz28

Well my old man insisted on coming up and giving it a try. Of course he wrapped the threads with some teflon tape and now it stopped leaking
But it's all good: I took him for a ride after we fixed it...in 8-10 footers. He's a boater and doesn't get scared at much, but when we fell off the back of a 10 foot wave he was ready to go back.
We weren't barely on a plane (20+mph?) but he was impressed how the 311 just sliced through the water and kept us dry.
Hopefully tomorrow I'll actually get to change props.
Thanks,
Michael