Best original style petcocks (fuel taps)

DogT said:

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On those type, the cylindrical rubber seal can swell and / or rotate and partially / fully block the fuel flow!

A full blockage is cool, your bike will die, but be unharmed, and other than being a PITA as it may take a while to find, there's no harm done.

A partial blockage may cause you to ride for miles on an inadequate fuel flow, and can lead to a holed piston etc.

Best place for them is the bin.

Prefer the stock, simple appearance of the factory type. The above photo looks like the taiwan, not UK, version.... screen and metal texture looks different. Might try rebuilding my originals first. They flow very good when open.

Rubber these days is lots better than it used to be. I'd give them a chance, not reject them out of hand. Where else are you going to get original looking ones, that's what the OP asked for, but then again they're made in Taiwan, so maybe that lets them out. Plus they're not $300 each.

Yes, the originals flow great. I'd use them if there was any chance of getting them lined up right. Maybe you have later ones with the lock nut, but I'd keep an eye on them for leakage and unload the gas if stored over winter. Like I said, I had good luck getting my originals to seal good enough.

DogT said:

Rubber these days is lots better than it used to be. I'd give them a chance, not reject them out of hand. Where else are you going to get original looking ones, that's what the OP asked for, but then again they're made in Taiwan, so maybe that lets them out. Plus they're not $300 each.

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I've already answered that Dog... Original looking ones, but with a brass taper, are available from various sources. Andy Molnar is probably the most expensive source... at £14.00 each !!

How much are new pistons ?!

And with respect, the issue is not availability of good rubber... the issue is: what kind / quality of rubber was used in the taps... and how do you know? But in essence, you are right to state the alternative, we all make our own decisions re our own bikes. It's the OPs prerogative.

Yeah, I missed the Andy thing, sorry. But I wouldn't have any problem without the reserve, my early F/G tank doesn't need the reserve taps. I'd like to see them. Price is reasonable, but shipping to US may be prohibitive. BTW the rubber in my BAP taps has been good for 4 years now, but I'm using avgas, not ethanol. That may make a diff too.

The Scott parts ones look the proper engineered solution to me. I've got a box of shagged out BAP and original style taps. Most BAP taps are not the real thing.

On the right is the later EW petcocks that don't have leaking issues. I've modied a few like this (quick turn on the late to put a groove, and add the O ring). They outflow nearly anything out there, and are awesome. On the original it's just the metal surface that seals. It'll work with lapping if there is only a tiny bit of damage and everything is more or less ok, because the spring on there presses one brass taper onto the other. If you lap it too much, the taper will only seal where lapped and won't seal as the thing wear (you'll have to keep re-lapping it). On the left is the emgo one, It leaks easily when that damn rubber bit swells and basically just drips down the handle. One of my more regrettable purchases. You can also see that the thing doesn't flow that well, and when it that's when the rubber and the hole in the petcock are actually aligned. They tend to go out of alignment.



You can see here the clear difference in flow. If you have a brass on brass taper, the O-ring groove works very nicely, only catch is that the petcock can leak slighly when closed if you don't do it right. You'll have to play around with the sizing based on the O-rings you buy. If the O-ring is too big, the brass to brass taper will leak when closed, which is not a problem if your carb slides are not sticking. If the O-ring is too small or non-existant, the petcock will likely be sealed when closed, but leak a bit through the handle when open.

Will buy a set of UK-made 14GBP versions to try. Would like to find someone to rebuild my originals, to compare and have as a spare set.
Not interested in BAP which I can't get past the looks on a Norton.

elefantrider said:

Not interested in BAP which I can't get past the looks on a Norton.

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I'll have to agree, but after I put them on it's hard to make the time to get them off. Maybe this winter. At least they've been working. 4 years ago there wasn't much choice with out spending big bucks.

How does the reserve work on the UK made taps? Are there two positions of the lever - one for taking in fuel above the stub pipe and another position for taking in fuel below the stub pipe?

Been a while since I used a set.

I have the RGM British made ones. Just like the originals.