Bridgestone Motorcycle Parts Discussion Board

Bridgestone Tech Talk => 350 Talk => Topic started by: BRT-GTR on October 11, 2016, 08:04:27 AM

Title: Removing brass tubes in Petcock and overhaul.
Post by: BRT-GTR on October 11, 2016, 08:04:27 AM
               Picked up a GTO fuel tap recently. Both brass tubes broken and in poor condition. Remembered Moonpup's post on the subject and thought I'd give his method a try.
             http://bridgestonemotorcycleparts.com/index.php?topic=4165.msg24211#msg24211 (http://bridgestonemotorcycleparts.com/index.php?topic=4165.msg24211#msg24211)

However, a 4mm tap wasn't biting into the tube enough to give a thread I could pull on. A 5mm would be too big. So what to do.    I found a 50mm x 4.5mm hardened woodscrew. One of the modern type, possibly sold as chipboard screws. Made up a spacer to leave half an inch projecting and wound it into the tube. Hey presto, both tubes came out easily.
  Already had some 5mm brass tube from my aircraft modelling days, thicker wall than the tube supplied these days. Put a taper on the bottom end and used a 3mm alloy rivet to tap the tubes in. Just make sure the tubes are upright before tapping , doesn't take much to tap them in 8-10mm.  Job done. 

   The filter bowl was full of the usual evil smelling gunge, cleaned it out and found the bowl had corroded right through in 3 places !! Luckily I had an NOS bowl.
  Made up some new filters and a bowl screen from 100 gauge brass mesh and new rubber washers from 2mm viton sheet. Just ordered 2 Honda type seal washers (4 hole type) from a garden supplier at a very reasonable price. Will let you know if they fit.

  Gave the tap body a quick 5 minute dip in Evaporust (Deox-C in the UK) and polished with a brass wire brush. This cleans zinc alloy very well and the shine seems to last.  Might try it on some corroded carbs.

   Here's the final result.

 
Title: Re: Removing brass tubes in Petcock and overhaul.
Post by: moonpup on October 11, 2016, 08:24:56 AM
Very nice job Brian.... Excellent!

Not sure why the 4mm tap didn't work for you, but at least we now have an alternative with the wood screw. Hey, whatever gets the job done is what I always say.  ;D

Also glad you mentioned tapering the ends of the brass tubes, as I forgot to do that in my thread.
Title: Re: Removing brass tubes in Petcock and overhaul.
Post by: BRT-GTR on October 12, 2016, 03:25:32 PM
 
            Thanks Mike.
        The Honda seal washers arrived today, unfortunately they don't fit being too small !! :'( .   You can't win them all.

         Fortunately my son in law has a Honda mower, guess who will be getting a surprise early Christmas present   ;
                 Brian.
Title: Re: Removing brass tubes in Petcock and overhaul.
Post by: OldSwartout on October 12, 2016, 05:32:38 PM
Richard Clark did have 350 petcock repair kits. Steve Reed had them made a few years ago, then Richard bought the stock Steve had left.  They worked well and had all the parts needed.  You might check with Richard to see if any are left.  They were a bit expensive, like anything made specially in low quantity. 

BTW, I tried a Honda CB450 repair kit and found it was the wrong size, also.
Title: Re: Removing brass tubes in Petcock and overhaul.
Post by: moonpup on October 12, 2016, 05:49:33 PM
A while back while searching the web, I found this site in the UK that has them. (or at least did at one time)

http://www.nrp-carbs.co.uk/shop/index.php?route=product/product&path=42&product_id=2879
Title: Re: Removing brass tubes in Petcock and overhaul.
Post by: BRT-GTR on October 13, 2016, 08:41:00 AM
    I know it's been done before but here's my take on the petcock refurb and the overhauled tap ready to go with a few spare bits.

     

       Mike, Did buy an NRP kit last year, a lot of bucks for what you get and you still need the filters  :-\

             To make the bowl filter and two rubber seals (bowl and tank union) I found washers the right size, punched the inner hole first and then cut round the washer to complete.  Takes minutes. (takes longer to find the washers!)
            The tubular filters for the petcock and oil tank take a little longer, rolled the brass mesh round a 5mm dowel, put a 90 deg bend on each end and formed a double lapped seam. Then used the 6mm brass mesh disc, left over from the bowl filter to cap the end with a run of solder. Almost a factory replacement filter which can also be used on the oil tank.

    Can now make all the parts required except for the special seal washer, if we can find a reasonably price alternative, job sorted.
        Brian.
Title: Re: Removing brass tubes in Petcock and overhaul.
Post by: moonpup on October 13, 2016, 05:50:48 PM

...snip....  if we can find a reasonably price alternative, job sorted. ...snip...

If product liability insurance wasn't so expensive & lawyers so prolific, I could provide them.  ;D
Title: Re: Removing brass tubes in Petcock and overhaul.
Post by: hardy on October 13, 2016, 08:49:34 PM

...snip....  if we can find a reasonably price alternative, job sorted. ...snip...

If product liability insurance wasn't so expensive & lawyers so prolific, I could provide them.  ;D

And I would stand by their quality!