Fuel petcock teflon tape

F

fast_eddie

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SYDNEY
Should I use teflon tape on the fuel petcock thread joining to the fuel tank? I didnt find anything when I took them off. Never leaked even without it.

Cheers
Ed.
 
IF at least one of the connecting halves is brass then you shouldn't need any: 'don't fix what ain't broke' etc
 
I use teflon but it has to be installed carefully. Do not allow any tape to be exposed inside the tank or fuel system as it will end up as a Milky Goo and plug things like your Carb Filters and Jets.

Something like to days Gas does but it don't eat your carbs - LOL
 
If you have the original tank spigot and petcock arrangement, they're not designed to seal via the threads so never had thread tape when they left the factory. One of them is R/H thread and the other L/H (can't remember which is which - i think the tap is L/H). The nut that holds them together has a different hand internal thread in each end. As you do up the nut, the two threads on the tank and petcock draw the spigots in intil their ends butt together. The original sealing method was a fibre washer that gets pinched between the ends of the two spigots, which works perfectly well as long as the spigot ends aren't dmaged. Don't be tempted to use an o-ring instead of the fibre washer because it'll squish inwards and pop out from between the two spigot ends (seen that done - unsuccessfully). The correct fibre washars are readily available for a few cents.

If you put a tank without any petcocks down on the floor, it'll rest on the spigot ends. Make sure they're protected or you might end damaging the sealing surface. I bought a second-hand ducati tank on eBay a few years ago, and the spigot ends looked like they'd been dragged down the road. It took quite a bit of honing  with an oilstone to clean them up, being careful to keep the stone square to the axis of the spigot. Damaged tank spigots may be why some people resort to thread tape.

Sealing the threads with tape is a workable alternative to the fibre washer, but a bit more messing around and possibly not as reliable. However, don't use the normal white plumbers tape because it is not fuel resistant. If you want to use thread tape, get the yellow fuel and gas resistant tape - this stuff: http://www.sealtape.com/ptfe_yellow.html

Cheers,
Cam
 
not fibre Cam (although that would work) but black plastic
very often they are missed, but get re-installed since they (very often) stay with the petcock unless the filteris removed , which is threaded nto the petcock, and should be unscrewed every now and then for cleaning, and blowing througn of the reserve standpipe (which can be cut lower on round badge tanks) since the "extra" capacity over the 1200 type tank is all carried along the base line of the tank.
CLEM
 
I struggled for years in my job trying to seal hydrocarbons.
Although not applicable in this instance (as the seal is on the washer, not the thread) Loctite 577 is the absolute ducks nuts for sealing problem connections.
I always put a little bit on my sump plug which seals lovely and has the added bonus of being a locking agent for the thread - so NO overtightening.
 
Clem, new fuel taps come with black plastic washers. Older ones came with fibre washers.
Fibre washers are readily available from the usual suspects.
I know because I bought a bunch of them recently.
 
A different question on the same topic. I have seen several "original" type replacement petcocks on the net, any comments on the fit and function of these replacements. And, for the original ones, are there spare parts to rebuild them? Trying to keep the resto as original as possible but parts sourcing can be a bit of a challenge.

thanks.

Clay
 
Original is original.
Replacement (copy) fuel taps are now only available in reduced sizes for some reason.
The cube type has a smaller cube (and nut), and the Paoli type with plastic lever is also only now available in smaller body size. In addition the taps do not both face forward when in the off position, The right hand one does, but the left one faces backwards.
The all-metal BAP type taps are again smaller in body size.
No idea what fuel flow is vs each other.
As far as I have found only the fibre washers are still available.
The cube tyoe easily dismantles, but the Paioli type is either screwed or riveted together. If screwed then no big deal. If riveted then you have to faff about finding the right size screws and then self tap or tap out to the right size.
I have not found a source of the rubber seal inside these taps yet.
 
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