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Petcock rebuild kits

Discussion in 'The Garage' started by ThatXS650Guy, Aug 16, 2014.

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  1. ThatXS650Guy

    ThatXS650Guy More Sparky than Speed Racer XS650.com Supporter

    Hey Gang, Just getting started on my $200 `78 Special. I want to treat the tank for rust but I need to figure out the petcocks first. I see I can get a rebuild kit form Mikes for $40 or so but all I really need is the 4 hole gasket. Will one from another bike work? Also, I noticed Z1 sells 650 petcock kits for a little less than Mikes. Will these work on my Special?
    http://www.z1enterprises.com/ItemDetails.aspx?itemDescription=Petcock+Kit+XS400+XS500+XS650+XS1100&item=KL18-2697
    My O-ring between the tank and petcock does not have the sections but the outside shape looks about right.
    TIA,
    Jim
     
  2. blue900

    blue900 XS650 Addict

    On my 81special I did not seal the tank just cleaned it out. I have a filter before the carbs and i do find a very small amount of fine rust in the bottom of carb bowls when make tuning adjustments, less as time goes on.
    I don't buy Mikes parts unless I have to, the rubber parts I got years ago where not great quality.
    I bought 2 of the Z1 kits Last year they seem good quality, and I have my vacuum petcock back, ( ran a mikes Manual for a few years on my daily rider it was starting to leak).
    One problem on my kits where they didn't seal, I found the problem and discribed it here
    http://www.xs650.com/forum/showpost...st.php?p=368087&postcount=14687&postcount=146
    -
    Be sure and rebuild as described here http://www.xs650.com/forum/showthread.php?t=20662
    My rebuild has been working great all summer.
    I just used the other kit for my other project bike and tested it, same mod but easier the second time.:)
     
  3. gggGary

    gggGary Stop that! Top Contributor XS650.com Supporter

    IIRC you gotta watch 78 petcocks they are a one year only deal? First year for the vacuum operated petcocks.
    This "looks like" the right kit for you.

    My bad; link was to wrong model.

    The petcock rebuild thread thread above is a good one read it and pay attention, details matter on petcock rebuilding.

    I always razor blade all the paint from the tank petcock seal area. then fine sand like 320 or 400 grit it till it's smooth, rough or peeling paint here will cause leaks. Any paint is ALWAYS rough and peeling.
     
  4. ThatXS650Guy

    ThatXS650Guy More Sparky than Speed Racer XS650.com Supporter

    Thanks Blu. I am not coating the tank I am doing the battery charger trick to it. I didn't want to invest the $$ into the coating until I am sure I want to use that tank.
    I tried the link but it is about using Forward controls?
    Excellent petcock rebuild how to.

    ggary, The eBay link was for a 750. Will that work for my 650 Special? I like the price. I've rebuilt a few petcocks so as long as the parts are corect I know what to do.

    Thanks!
     
  5. gggGary

    gggGary Stop that! Top Contributor XS650.com Supporter

    Sorry about that, was too fast on the cut and paste. The parts fich lists 78-79 as using the same petcock. It also lists 80 but I'm pretty sure that's wrong, the 80 is BS34 and one petcock. I have rebuilt 79 petcocks just don't remember where I found the parts. There are a bunch of similar petcocks that use different size 4 port seals.
     
  6. gggGary

    gggGary Stop that! Top Contributor XS650.com Supporter

  7. ThatXS650Guy

    ThatXS650Guy More Sparky than Speed Racer XS650.com Supporter

    Yeah, if I could find just the 4 hole gasket I think I can save the rest or use McMaster Carr o-rings for the petcock to tank and the lever.
     
  8. 5twins

    5twins XS650 Guru Top Contributor

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    Sometimes you can just flip the 4 hole rubber disc over, revealing it's unused backside, and get more use out of it. I'm pretty sure that oddball petcock was only used on the '78E, the Standard. A couple local guys have matching '78 Specials I've worked on and they have different petcocks than my Standard.
     
  9. gggGary

    gggGary Stop that! Top Contributor XS650.com Supporter

    For my money the kit at $15 shipped is the better deal. Yes I fit stock o-rings for the tank to petcock junction. They are nice and fat and you usually have to assemble loosely then finish pushing them into place but they seal great!
     
  10. ThatXS650Guy

    ThatXS650Guy More Sparky than Speed Racer XS650.com Supporter

    It's a good deal but is the 4 hole the corect size?
    5Twins, one of the 4 hole gaskets is torn so it will need to be replaced.
     
  11. 5twins

    5twins XS650 Guru Top Contributor

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    Something usually not mentioned in overhaul threads is to check the holes on the flat backside of the lever part. If they are sharp edged, that's what tears up the rubber disc when you rotate the lever. I "break" or round off those sharp hole edges with a small sharp pocket knife.
     
  12. ThatXS650Guy

    ThatXS650Guy More Sparky than Speed Racer XS650.com Supporter

    Good tip. Thanks again 5Twins
     
  13. gggGary

    gggGary Stop that! Top Contributor XS650.com Supporter

    Sand the lever on 600 grit on a flat surface then power buff it till it shines. That gets rid of the grooves where dirt has worn it way and the buffing breaks the sharp edges. This info is in that overhaul thread you didn't need to read (wink). Yeah I had rebuilt 20 or 30 petcocks and still picked up some tips from that how to.
    Note; I didn't write it, just borrowed with permission.

    IMHO do NOT bother flipping the washer no matter how good the back looks (personal experience). I hate removing and draining the tank the second time! A new valve (what Yamaha calls the 4 hole gasket) is a must, like throttle shaft seals, it just ain't worth taking the chance of having to do the project twice. At 35 years old the rubber is well past it's use by date.
     
  14. ccline746pk

    ccline746pk XS650 Enthusiast

    Gary,

    Are the rebuild kits from Mikes any good? Or is there a better quality alternative?
     
  15. gggGary

    gggGary Stop that! Top Contributor XS650.com Supporter

    I have had success with the mikes kits. used 4 or 5 so far on various years.


    These on fleabay for the special petcocks worked good for me. at $15 delivered I think they offer good value.

    I'll repeat; it's not just throwing in the kit, attention to the flat surface of the selector and being SURE the bevel seat for the vacuum seal will stop gas flow are critical, if you aren't willing to get those things right, save frustration and just buy new petcocks. Scrape any remaining paint off the tank where the petcock seals and fine sand that area smooth.

    OK I'm off my high horse, it would be nice if you report back what you do, how it worked (or didn't) for you.
     
  16. ThatXS650Guy

    ThatXS650Guy More Sparky than Speed Racer XS650.com Supporter

    Got the $15 kits from eBay. Everything went together pretty well and I am pleased with the results. I need to clean the tank before I put gas in it but all indications are the petcocks will function well with the $15 kit. Nothing wrong with saving a few bucks...
    Thanks everyone,
    Jim
     
    Last edited: Sep 25, 2014
  17. jetmechmarty

    jetmechmarty XS650 Guru Top Contributor

  18. gggGary

    gggGary Stop that! Top Contributor XS650.com Supporter

    There's an echo in here.

    That great xj thread is also on this site (with author's permission) a link to it is in a reply above.
     
  19. jetmechmarty

    jetmechmarty XS650 Guru Top Contributor

    I guess I need to pay closer attention. :shootme:
     

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