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How-To: New fuel filler mod for a 510

Creepy Cruiser

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Are you tired of fuel dripping inside your trunk?

Are you tired of getting high from the gas fumes when you go to the grocery store?

Are you tired of fuel pouring out on the side of your car, when you hit those hard left hand turns?

You say you don't have $250 for a NOS, out-dated OEM rubber filler hose for your 510?

Then this quick easy cheap mod could be for you. (no welding involved)


This is a HowTo, on another way to replace that old rotted out filler on a 510 using about $10-$15 in wrecking yard parts.


My goal was to come up with a filler neck that was super easy, super cheap, and didn't require any welding. I'm a fabricator myself, so I can build anything I want, but I wanted the challenge of coming up with one, without using any expensive tools, lol.


I did not remove my tank to install this, The tank you see in the pics, is an extra one I have around for mockups.





Parts needed:

1) 88-93 Mazda B2200 filler neck

2) 91 Isuzu Pup filler hose (not sure what other years match it yet) (If anyone finds a good source for NEW hoses please post it)

3) A couple feet of new 5/8" vent hose

4) A newer style plastic (thread on type) Nissan gas cap (or the Mazda one that was on the filler when you got it at the wrecking yard)



Tools that help make it easier:

1) Basic 4 1/2" grinder (can be done with a hacksaw and flat file if needed)

2) Harbor freight med size tail pipe expander (not needed but helps) I think I paid about $8 for it.

3) Heat gun or blow dryer



This is the ugly thing that has been in there for way too many years: (It had to go)







***You do not need to remove the tank to do this mod.***


I'll be showing a modded and un-modded part of each thing.



So we start with the 91 isuzu rubber filler hose. I cut 2" off one end and 1" off the other end like so. (note where the bend is, so you cut the right amount off the correct ends)






Next we grab the Mazda B2200 filler neck and cut off the extra hanger.






Then we take the 510 gas cap ring and make the inside hole larger. I do this by just grinding the top of the bump down, until the center falls out. (then it's just the right size with a perfect round hole)








Now we have this:






Now working with the end that I took 2" off, insert the expander into the hose about 3" or so. Then use the heat gun to warm up the rubber, (slowly expanding it), until it will fit over the fuel tank opening.







Then mount the neck itself (the metal part) using the original 510 ring we modded on the outside. Make sure to mount it with the hinge of the flapper door on the top, and so the vent tube faces the rear of the car. Make sure the vent tube doesn't get in the way of the trunk hinge.






Then hook the rest up and it should look like this.








Now this is in no way the only way or even the best way to do this, but it was a fun project, and makes it so much nicer at the pump. No more gas fumes is a great bonus as well, lol.


So as for testing so far:

It fills up like a normal car now, it's great. You can lock the handle and go. I haven't filled mine to the top yet though, (I only run my tank half full for weight balance), so maybe someone else can report back on that some time. I ran the crap out my car, (drifting around corners etc...), and it never drip at all on the inside or outside. No more smell. The only minor hiccup i've found so far is, if you are not careful, you will drip a little fuel when you remove the pump handle because of the angle.




Let me know if you have any questions



*****This is a post on how I did my own filler neck, I am in no way responsible for anything anyone else does to them selves or anyone else by reading this information. Read at your own risk. Fuel is very very dangerous and can kill you in more ways than one. Do not try anything like this at home*****

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Great write up! :thumbup:   I see you also had to re-drill the mounting holes on the Mazda unit.  Does the cardboard panel fit back in place?


Yes, I just used self tappers for mockup (seen in the pics), but I now have some nice allen head bolts for it.


That is a very good question on the cardboard. I don't have one in my car, so I don't really know.

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Id like this, but....................., it deserves a better response.


Excellent write up and great scavenging of parts from other makes and models.


This is a problem we have here as well and is a great solution, now if only I can scour the wrecking yards here in Aus for the bits.

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No worries at all.


I did mine based on a "no welding involved" version, (for those who don't have access to one.)


What neck are you using?


Do you have any minorl issues with yours at all? (shutting of early, leaking, dripping when you pull the nozzle out, etc...)

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I believe the neck was off of a eagle talon? I forget. I had the car, and chopped it off. It was off of a DSM I know that. 

Yeah not everyone has access to welding, I actually asked the exhaust shop that bent and enlarged the main tube if he could weld it for me, cause I was unsure of my welding abilities. I guess I did good lol.


No issues whatsoever. The only issue is when I pull the nozzle out, the last few drips always get on the paint due to the tilt (or lack of) but thats with all my cars. Just a couple shakes and it solves that issue 

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this is awesome 2 ways to mod your NLA fuel neck both very easy 

Thanks guys they both look great 

If I didn't already buy an nos rubber one I would be doing this mod tomorrow 

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I'm posting this link here, not to step on any shoe laces, but to help the next person searching for ideas.  Likewise, I'm putting a link to this option, on the other post.





I hope you don't mind Creepy...

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Here is another method:





Okay, so long time no post lol, decided to tackle making a new filler neck for the dime, old one was pissing fuel....


Things youll need,


240sx filler neck


1 7/8" OD to 2.25"ID exhaust reducer, 240 and 510 use diff diameter hose



2.25" ID curved tailpipe



2.25" ID fuel hose


5/8" to 1/2" reducer for vent line, i used a copper pipe



1/2" ID fuel hose

hose clamps



Cut the filler neck pipe off just before the curve, trip the shroud around the cap area down to around 1/8" to 1/4", just enough removed to be able to fit it thru the hole from in the trunk to the gas door pocket.


Weld the reducer onto the filler neck like so.



Rather complicated compared to some, but i holesawed the center out of the factory 510 fuel cap holder to match the OD of the filler neck just behind the shroud, i think cut the plate in half and used it as a sort of "split ring retainer" for the filler neck. stick filler thru the body, then half at a time slide the plate peices onto the filler and lock em down with the screws.


Now that the filler is secured in the body, cut the ends off the curved tailpipe so you have a useable slight bend peice that fits into the 2.25"ID fuel hose. Cut sections of the fuel tube to connect the filler to the intermediate section, then to the tank.


I used an exhaust expander to stretch the hose just a bit to be able to slide it over the exhaust expander welded to the filler, intermediate pipe had no issue.


The vent line on a 510 is 5/8", a 240SX is 1/2", use your reducer in the hoses and get it connected up. I went hose clamp crazy because im paranoid.


Thats the ridiculously short and simple explanation of how I did it...

















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