Aftermarket Fuel tank question

79josh81

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This might be a dumb question but I'm looking to eventually buy an aftermarket fuel tank and it has 3 petcock ports already welded into the bottom of it.

friscotank.jpg

I will probably be using the two 1/4"NPT fittings for petcocks. My potentially dumb question is what is the best way to seal up the larger 3/8"NPT port? I'm just curious what others have done.
 
Go to the plumbing section of the nearest hardware store and buy a 3/8" NPT plug. Wrap it with fuel-rated yellow Teflon tape and screw it in. If the plug has flats that protrude more than you want to see, apply the bench grinder. If you want the plug to sit flush, level it on the bench grinder, clamp it in a vise, and cut a slot in it with a hacksaw so you can turn it with a screwdriver.
 
I have the same type of tank. I scavenged a low fuel sender from a Honda Magna, ran a 3/8" NPT die over its metric brass threads and will insert it in that large bung with fuel resistant Teflon tape. So, I won't be messing with a fuel reserve or watching the miles ridden, I'll have a low fuel warning light instead.

Or, Use a galvanized pipe plug.

Scott
 
Ok thanks. That was the obvious choice I had in my head to plug the hole, I just wasn’t sure if it was that simple or not. Thanks guys.
 
I have the same type of tank. I scavenged a low fuel sender from a Honda Magna, ran a 3/8" NPT die over its metric brass threads and will insert it in that large bung with fuel resistant Teflon tape. So, I won't be messing with a fuel reserve or watching the miles ridden, I'll have a low fuel warning light instead.

Or, Use a galvanized pipe plug.

Scott
...and that is a really cool idea.
 
Go to the plumbing section of the nearest hardware store and buy a 3/8" NPT plug. Wrap it with fuel-rated yellow Teflon tape and screw it in. If the plug has flats that protrude more than you want to see, apply the bench grinder. If you want the plug to sit flush, level it on the bench grinder, clamp it in a vise, and cut a slot in it with a hacksaw so you can turn it with a screwdriver.

Hi grizld1,
I've seen pipe plugs that have an internal hexagon in 'em (or buggrit, was it a square? It was years ago.) so they'll thread in flush.
 
Good catch, Fred. Guys, let's not go all AR on this: plugs and fuel tanks are different critters. I don't suggest or recommend what I haven't done, and I've had a galvanized plug in my gas tank for years.
 
Well...looks to me the two back ports are to be connected to each other so tank sides equal level...front port is petcock...
 
Well...looks to me the two back ports are to be connected to each other so tank sides equal level...front port is petcock...
why wouldn’t you use two petcocks down there? With how high the 3/8 port is and the way this tank follows the backbone angle, you’d be leaving a lot of unused fuel in the tank if you only used the 3/8 port.
 
Well...looks to me the two back ports are to be connected to each other so tank sides equal level...front port is petcock...

Those bungs could be used for different purposes and combinations on different bikes. On my bike the two rear outlets are the low point of the tank, works best for me. I use two petcocks because each of my carburetors has an inlet. My carburetors have a crossover tube between them, no need for any other equalizer.

Scott
 
IMG_20180905_153131.jpg
Dirt bike and atv tanks use ports to level fuel side to side. That what I did on bike in picture too because 2 sides not really connect except at top...use 2 petcocks and plug if you think it better.
Those bungs could be used for different purposes and combinations on different bikes. On my bike the two rear outlets are the low point of the tank, works best for me. I use two petcocks because each of my carburetors has an inlet. My carburetors have a crossover tube between them, no need for any other equalizer.

Scott
 
why wouldn’t you use two petcocks down there? With how high the 3/8 port is and the way this tank follows the backbone angle, you’d be leaving a lot of unused fuel in the tank if you only used the 3/8 port.

I have a similar tank mounted on my bike. It could be done depending on how far down the backbone it is mounted. It is real close to the valve covers if you would use a large petcock on there.
 
This scenario too. With a big tank you run out of fuel, you switch to reserve, you're riding along and you run out of reserve fuel, no problem, tip the bike on its side and you still have one more reserve. Just as life was intended, you always get that second chance.

Scott
 
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