350 GTO Petcocks.... A Photo Comparison

[moonpup]

The GTO's had two different style petcocks/fuel taps. There are a few pictures of the early ones here & there on the site, but I thought I'd post up a more in depth side by side photo comparison of the two.

The early one (1970) shared the same main body as the GTR and could easily be changed back and forth between the two with a simple swap of the turn handle & numbered face plate.

Whether one is better than the other.... I have no idea, but at least gasket/screen kits are available for the early ones! 

The early petcock is the one on the right in all the photos....

(Edited 10/23/23 with more accurate information)

[moonpup]

more photos....

[dcr]

It appears as if most of the bikes had various petcocks over the years. I have 3 single cylinder Bridgestones and they are have different petcocks. Perhaps a page of petcock pictures is in order? Say that 3 times fast.

[slawsonb]

Vely intelestink....and diverse.
 
...bert

[coxy]

yes very interesting .
hey mike if you still  have the pet cocks in pieces do you think you could get the size and pitch of those 2 little screws that hold the tap and face plate on for me please  cheers coxy

[moonpup]

I'll see what I can do for you coxy, but at the moment I have no means to measure them. Maybe someone else already knows the answer and will chime in....

[BRT-GTR]

Coxy,
        It's your lucky day, I'm just overhauling a couple of petcocks. The 2 little screws are 3mm dia and 0.6 pitch, so are not to ISO standard (0.5 pitch). If you are stuck, identical screws are used inside the left handlebar switch case to hold the wiring guide plates in place.
      While we are on petcocks, the tank union nut needs replating on one of mine. Anyone tried drilling out the securing pin which is pushed into a hole on one of the union nut flats. Would this release the nut from the petcock body ?
 Brian the Brit.

[moonpup]

Thanks Brian, I was trying the think of another piece that may have used the same size screw and totally missed the switch case. 

Here's the part number for them... 0311-0306

[coxy]

legendary stuff that's great  news I have plenty of spare switch blocks.cheers

[Colin]

So what's that then DCR Peter Piper picked a peck of pickled petcock pictures, 3 times fast you say  

[steve]

The tap in the left of the picture with the larger bowl...has anyone been successful in buying a replacement seal kit for one of these?

Thanks, Steve

[moonpup]

Steve, I haven't checked with Richard yet to see if he has any, as I hadn't actually intended to use this style on my resto.

The seals for both the bowl and the large attachment nut at the top look like they'd be pretty easy to replicate. They're just 2 flat washer shaped rubber pieces.

The hard one is going to be the one inside the body used for sealing the tap/turn handle. You can see it in the second to last pic above. It appears to be a brownish compressed material (cork?) and is approx. 1/2" thick. Have no idea where to get that one!  

[disc_valve]

Hi again, Brian,

Re your query on drilling out the little pin that retains the fual tap nut. It may not be as simple as that. I've never neede to try on my 175 or 350 taps, but my BS90 has a late type tap with what looks like the same method of retaining the nut. However... - on one of the spare taps I had had a small length of "pin" which was poking out of the hole, just enough to be able to grip it and pull. What came out, though, was not a pin, but a length of soft iron wire that wrapped right around the inside of the nut in a shallow groove, and fitted underneath a small lip on the tap body, hence retaining the nut in place. If the 350 tap is the same, you'll need a very long drill that drills curved holes!

Unless the end of the wire is accessible, I can't think of an easy way to remove it without butchering the nut.

Graham

[BRT-GTR]

Hi Graham,
               Thanks for your reply - once again , the fount of all BS knowledge  , (Well most of it, anyway)

   That explains that one, I did wonder how a single straight pin could retain the nut. Now I know what I have to do, I will have a play with it and see if I can get the wire out. I notice the hole is lightly punched to retain the wire.  Now where can I get one of those curved drills ?? . 
The gas and oil lads can drill curved holes and are able to make the drill string curve outwards horizontally from the well head to increase production. Clever, but I think they may be working on a slightly bigger radius of curve.
   Another bit of info, one of my later type petcocks has a steel union nut and the other one has an alloy nut. I may just try home plating the steel union nut while its attached to the main body, what could possibly go wrong.
Brian.

[Colin]

Oh yes Brian I like your train of thought, what could possible go wrong 
btw I'd try that too

[slawsonb]

Glad to hear all possible bad outcomes don't happen in the UK as they don't here in the US...guess BSers are immune...lol
Wonder how that pile of scrap in the corner got there 
 
...bert

[BRT-GTR]

Hi Bert,
          Nothing ever goes wrong here in the Uk  ....................................... apart from..........................how long have you got? . No wonder we get cynical later in life. Just spent a few weeks trying to reduce the pile of scrap(not BS stuff) in my workshop so I've got some space to work, getting there slowly.

   Re the seal on the early tap, it probably is a cork type which was commonly used on early petrol taps, as you will know. Steve, I  have seen wine stoppers made from high density, reconstituted cork which might give you a source of material to have a go at making a new seal. It wouldn't need to be too accurate because the cork swells when wetted. I don't know what was used to bond the cork, maybe test some in petrol first but worth a try if you are stuck.   
   Brian.

[Colin]

you can buy sheets of cork like gasket material and I have just posted this one as an example
colin

http://www.baysidemarine.co.uk/cork-gasket-material---300mm-x-300mm-x-2mm-1389-p.asp?gclid=CNq2iNCF9cECFXKWtAod5GIAmw