BING petcock conversion bung

[Lmo]

I've been kicking around the idea of converting my old Dnepr tank to twin petcocks; we all know how much of a PITA a single petcock is. I' happen to have a couple of spare BING petcocks so that's what I'd use. New they're about $70, each, but they're widely available on eBay, etc. "Used" is no problem; they are rebuildable. A point I like is that they are easy to remove/replace with a single wrench.

https://bingcarburetor.com/petcocks.html




The problem is, or was, the fuel tank bung. Silver solder in place.

Not now > http://www.bungking.com/20mm-petcock-bu ... CS4mC7wKH0
NOTE: the "long" version has been discontinued, but the short one is the one needed with Karcoma petcocks.


A cross over fuel line is easy with a couple of "T" fittings.

And just like that, voila... no more fighting the freakin' cross over tube fuel flood when removing the tank.

[Tomcatfixer]

Brilliant, Lew.

A cross over fuel line is easy with a couple of "T" fittings.

But will two petcocks, why even BOTHER with the crossover? Unless, of course, one of the carbs is more "thirsty" than the other.

[jeffsaline]

Chad,

Two petcocks with the crossover allows both "sides" of the tank to equalize fuel levels.

Best,

Jeff

[Desantnik-VDV]

It's been done before. When I transplanted BMW R100 engine into my 99 Deco it was starving at 70-75mph freeway speeds. Single Ural petcock would not deliver enough gas to BMW engine at that speeds. Max speed I had was 90 mph for 2 minutes or so. A friend of mine was riding parallel to my line on his Honda touring bike and my Ural speedo was pritty much right. If I am not mistaking Richard Winter (Bural) had welded a second spigot to his Ural gas tank.

[Desantnik-VDV]

Chad,

Two petcocks with the crossover allows both "sides" of the tank to equalize fuel levels.

Best,

Jeff

Yeah, that's what crossover does, specially when gas gets lower in tank skirts.

[Tomcatfixer]

Fellahs, I understand the function of the crossover line. I just thought that, with properly balanced carburetors, each cylinder would consume fuel at the same rate, thereby lowering the fuel level on each side of the tank at the same rate, which would make a crossover line redundant.

BUT, as I said in my post above, I suppose the two sides of the engine will never consume fuel at the same rate. So, I guess a crossover line will always be necessary.

[Claus]

That´s why BMW decided to have a crossover line on about most models (R2V)

[rougaroo]

IMG_20190514_073050.jpg

Another way is to have a y-splitter on both petcocks, then connect one leg from petcock to petcock. That way you have a convenient way to turn the fuel off whenever you have to pull the tank. (Not that anyone has ever spilled gas all over from the crossover tube, you understand).

Rougaroo

[fencermatt]

Here's the route I took on my Dnepr:

• CJ750 tank with two bungs.
  
  Two Honda petcocks that have the same 16mm threads as CJ/Dneprs

I get good flow to my R80 engine. Only real issue is the petcock on the right is backwards, which means the lever positions are reversed. That's the nice thing about the Bing petcocks, they make one specifically for the right side.

[Lmo]

What kind of condition was the tank in Matt? I stripped the interior of mine, but I wouldn't be adverse to replacing it (the welds are horrible). Did it bolt up to your frame with minimal headache?

How much, if I may ask, do you have invested in the tank/petcocks (aside from paint, etc.)?

[fencermatt]

Hi Lew,

The tank is pretty solid. It bolted right up to my Dnepr MT-16, replacing the toaster tank. There is very minimal clearance between the tank and my tractor seat. I have to take the seat off to remove the tank, but it does fit.

In addition to the tank ($145 plus $30-ish shipping) and two petcocks ($25/each for Karcoma brand), I POR-15ed the inside and bought a better gas-cap seal from Old Timer's Garage. Because of the shape of the tank, when it's full gas can slosh out the vent in the cap. I ended up making a baffle to help keep the gas inside.

[INSUBORDINATOR]

Here is the common upgrade, Japanese fuel tap - used on Ural - UPGRADED to a dual outlet, by drilling out the opposite side of the die cast tap body, & inserting a correct size brass pipe for nipple (sealing with JB weld). Dual tap works great, eliminating T fittings.

[jaybird]

Here is the common upgrade, Japanese fuel tap - used on Ural - UPGRADED to a dual outlet, by drilling out the opposite side of the die cast tap body, & inserting a correct size brass pipe for nipple (sealing with JB weld). Dual tap works great, eliminating T fittings.

Nice mod

Happy trails,
Jaybird

[BinDerSmokDat]

Someone, UralDude I think, just runs his crossover above the spine of the frame but lower than the crossover nipples.
Think longer crossover tube but crossing the frame more rearward.
No issues removing tank, no disconnects or fancy hardware needed.

I don't remove the tank often so haven't felt the need to change anything.
I might his solution the next time I have the tank off.