petcock bung

[DRare]

Anybody have any info on a specific bolt or any way to plug the spare petcock hole for a 2.1 mid tunnel wassell? I threw a bolt in it and it still decided to leak gas. I would imagine thread tape wouldn't help me. When i pulled the bolt out the threads looked alright so i'm not too sure why it would still leak...92' sporty.

[farmall]

Bolts are straight thread not designed to seal. Most old tank bungs are tapered pipe thread so try a pipe plug (bring tank to hardware store). Seal with pipe dope or teftape which are the correct sealants for tapered fittings.

[Guest]

if it is a genuine British made Wassell tank, they were 1/4BSP thread..
in which the Female thread is parallel and the male thread is tapered.
made to suit the many types of British fuel taps used at the time

[DRare]

Thanks fellas. appreciate the replies.

[TriNortchopz]

" How to measure BSP Threads

One of the most frequent problems that we have found our customers run into is the identification and measurement of pipe threads.

In Great Britain BSP British Standard Pipe threads are commonly used.
These are either parallel (BSPP) which normally seal on a washer or 'O' ring seal, or tapered (BSPT) which taper along their length and normally seal by two mating threads.

How to measure your thread:

Use a tape rule (or vernier gauge) to measure across the outside of the male thread. Note that a thread that measures 1/2" is not a 1/2" BSP thread.

Using the table below we can see that a thread measuring 1/2" is actually a 1/4" BSP thread. Similarly, a thread that measures 1" is actually a 3/4" BSP thread..."

https://www.thehosemaster.co.uk/bsp-pipe-threads

[DRare]

Thanks Tri. It's not an actual wassell tank. It's a tank i got from Throttle Addiction. I've ordered pipe plugs from auto zone and we'll see if it works. Fingers crossed. Thanks for the reply and info though dude.

[farmall]

Throttle Addiction would or should know the thread spec but the reason I suggested a hardware store is they've examples of everything from 1/8" NPT (too small) on up. Your tank bung is probably 1/4" NPT.

You can measure using a caliper and know. (BTW Harbor Freight digitals work fine though their feel isn't gret, and are only around twenty bucks, every mechanic should have one and mine keep my Tesa and Mitutoyos safe in the machine shop.)

https://www.engineersedge.com/hardware/taper-pipe-threads.htm

https://www.harborfreight.com/6-in-digital-caliper-63711.html

[DRare]

Thanks for the help fellas. Got a pipe plug and it's leak free.

[farmall]

Thanks for posting the solution! It helps others.

[Guest]

if it is a genuine British made Wassell tank, they were 1/4BSP thread..
in which the Female thread is parallel and the male thread is tapered.
made to suit the many types of British fuel taps used at the time

Thanks for info, it's useful for me