Larger barbed fitting needed.

[Cowthief]

I purchased the Sierra 18-7353 fuel pump. Attached is the picture of the fuel out nozzle that is much to small for my 5/16th fuel line.

I have tried Lowes, Home Depot, Pirtek, Plumbing Supplies, Ace Hardware, NAPA, 3 auto stores, and Grainger. None of them have the same threaded ends for a larger nipple.

Anyone have experience in this or could point me in the right direction for a correct size. I tried to make it work but fuel went everywhere :facepalm: Any type of reduced I could use in the fuel pipes?

 

[gm280]

Re: Larger barbed fitting needed.

For starters that doesn't look like any NPT thread size to me. I don't see any taper (probably not either seeing the "O" ring seal). Do you know the actual diameter and thread pitch? One other option is to get a nylon or even a brass barbed fitting that will take the smaller hose size from that fitting on one side and the larger 5/16" hose like you need on the other side. Then IF the flow is not quite good enough, you could just drill out that brass fitting you are showing one drill size up at a time to increase the fuel flow. For example, if the inside diameter now is 1/8", use a 3/16" size drill for your first drill out, etc...

 

[Cowthief]

Re: Larger barbed fitting needed.

For starters that doesn't look like any NPT thread size to me. I don't see any taper (probably not either seeing the "O" ring seal). Do you know the actual diameter and thread pitch? One other option is to get a nylon or even a brass barbed fitting that will take the smaller hose size from that fitting on one side and the larger 5/16" hose like you need on the other side. Then IF the flow is not quite good enough, you could just drill out that brass fitting you are showing one drill size up at a time to increase the fuel flow. For example, if the inside diameter now is 1/8", use a 3/16" size drill for your first drill out, etc...

I have been told it was SAE threads. I got them to fit into an 8mm hole (Can't imagine it being metric, but it went without struggle). I don't know the pitch. Looks like I will be looking into a conversion piece such as the picture below with small fuel hose to larger.

 

[gm280]

Re: Larger barbed fitting needed.

I have been told it was SAE threads. I got them to fit into an 8mm hole (Can't imagine it being metric, but it went without struggle). I don't know the pitch. Looks like I will be looking into a conversion piece such as the picture below with small fuel hose to larger.

View attachment 186728

That adapter is exactly what I was referring to. Make the change over as close to the smaller fitting as possible to help with the narrowed flow...

SAE is standard (American) thread sizes. Another option is to retap the hole where that fitting installs. You could buy a brass nippled fitting for the size you need and then get a tap for that size and rethread the hole it fits into... So many options

 

[nwcove]

Re: Larger barbed fitting needed.

would 1/4 fuel line work ? if not, your local boat shop should have clear line that will push on over that nipple, and increase its od enough that a clamp will tighten the 5/16 id line up just right. ( you only need an inch of it or less, but its cheap by the foot)

 

[Cowthief]

Re: Larger barbed fitting needed.

Both awesome ideas guys. I like the idea of a small 3/16 line over the nipple and then the 5/16 just on top so it tightens down...never thought about that.

Gm280, the only problem is I am not familiar with tapping and rebuilding threads. I will keep all options open though.

Thanks again guys this site is always so helpful.