View Full Version : Vintage Wassell peanut petcock questions

12-29-2012, 3:15 PM
Sorry if this has been asked previously, did my best to attempt to search both the forum and Google prior but remain unsure.

I'm attempting to put an older style Wassell peanut on my 2 stroke bobber project and have 2 questions:

1) I have roughly measured the diameter of the holes in the standard bungs (2) on the tank and it's around 9-10mms. This is approximately 3/8ths of an inch. Do I purchase a 3/8ths petcock or do I choose one size smaller than the hole itself? (1/4" which the newer style of nut tanks sold by lowbrow and others use)

2) the tank has two holes, I assume that has something to do with the number of carbs? Or perhaps to allow for universal fitment? I'll only need one petcock so I was wondering the best way to cap the other hole. Should I use a bolt and some type of o-ring? Simply weld it?

Thanks in advance,


12-29-2012, 3:22 PM
the two holes could be a tunnel thing,when the gas gets low you will have some on each side,i hooked up both and one is like a reserve,hope this helps

12-29-2012, 3:41 PM
you need to use them both or you wont be able to use all your fuel most wassells have a high tunne;

12-29-2012, 3:46 PM
And now I know :) Thanks for the quick responses. Any ideas regarding petcock sizing?

12-29-2012, 10:18 PM
And now I know :) Thanks for the quick responses. Any ideas regarding petcock sizing?
1/4 NPT
Lowbrow sells'em.

12-30-2012, 4:32 PM
It should be 1/4" npt. It's a tapered thread so do not try to run a normal bolt through it. You can go to a hardware store and buy a 1/4" npt cap. Get a brass one and if you look you can find them with a allen head socket in the end and not the square slug and it will sit flush to the end.

If it's not not then it may be something metric or Brittish? My tank is a Daisho, looks identical to the wassel tanks, but had metric fitting in it. I ended up drilling and tapping them with 1/4" NPT. For your next question, yes a 1/4" petcock will supply plenty of fuel for about any bike. Mines a 1200 shovel and works fine. :cheers mate:


12-30-2012, 5:12 PM
I think the thread is BSP, could be wrong.

12-30-2012, 5:34 PM
ya, no tellin. Does it have a stamping on the inside of the tunnel?

12-30-2012, 6:39 PM
MOST of the original wassel tanks were BSP thread, a weird brit thread, NOT the same as NPT threads! That being said there were many types of wassel style tanks (but not British) being produced back then.