1. Dismiss Notice
  2. Dismiss Notice
  3. Hey Facebook people... We've created a group for XS650.com members to connect. Check it out!
    Dismiss Notice

Cleaning and rebuilding my XS2 carbs

Discussion in 'The Garage' started by eight0, Aug 4, 2017.

  1. eight0

    eight0 XS650 Enthusiast

    45
    34
    18
    London
    Hi All,

    So I've been reading this site, the carb guide and watching as many videos as I can about carbs and the time has come to take my XS2's BS38's apart. I should point out that I have never taken apart a carb before...

    When I bought the bike it ran but when the petcocks were turned on it poured fuel out of the overflows and out of the air filters (and probably into the engine too). The petcocks seem to work but they are stiff so I'm going to rebuild them with a kit anyway.

    Having taken the carbs to bits, one of the floats was full of fuel, the other measured at the correct height. I have only gone so far as to take the float bowl off the second one as I may need it as reference.

    I've bought an ebay ultrasonic cleaner, some 1x4 o rings for the needle jets and 4 OEM seals for the throttle shafts - I'm not sure if I need to replace these but I'm guessing they won't like the ultrasonic cleaner and I have no idea if they are bad so I may as well replace them. I've also bought some OEM float needles and seats.
    All the jets are standard and OEM and appear to be in good condition.
    2 things I have noticed so far, the Needles were set on ring 1 not 4 as the manual states and the fuel mixture screws were 3 turns out not 0.75, I'm guessing this was because the needles were sitting too low in the needle jet?

    I'm starting this thread mainly because I'm probably going to come across some problems and will require some help!
    I have a day off on Tuesday so I'm going to dive in then. Hopefully my JIS drivers I bought for the throttle shaft will have arrived by then. I'll try and take photos of my progress and upload them.
     
  2. fredintoon

    fredintoon Fred Hill, S'toon. Top Contributor

    Hi eight0,
    you will have noticed that the butterfly bolts' tails are peened over?
    You'll need to grind the bolt tails away to get them out and to buy new fasteners.
     
  3. eight0

    eight0 XS650 Enthusiast

    45
    34
    18
    London
    Thanks Fredintoon, yes I'll give that a go with a dremel. I have ordered some 6mm M3 countersunk allen heads as I saw someone else did. I'll put those in with some blue threadlock.
    I just hope they come out OK. I might give them a good spray of GT85 the night before.
     
  4. 5twins

    5twins XS650 Guru Top Contributor

    18,333
    8,565
    688
    You may need 8mm long screws, the 6's could be too short. Test fit one before doing the locktite thing to it.

    You can pull and inspect the condition of the outer butterfly shaft seal on each carb without pulling the shafts out. Just remove the cable arm, spring, etc. from the shaft and you can access the seal. They're not a tight, pressed in fit like a normal oil seal, they're very loose and easy to pop out.
     
  5. eight0

    eight0 XS650 Enthusiast

    45
    34
    18
    London
    Thanks 5twins, luckily I ordered both the 8mm and 6mm :thumbsup:. i'd really rather not replace them if they don't need it but I do have to take them out to put the carb body in the ultrasonic cleaner. Silly question then.. if the seals are so easy to remove why do you have to take the shaft out? I don't have the carbs in front of me so it will probably be obvious when I take a look.
     
  6. 5twins

    5twins XS650 Guru Top Contributor

    18,333
    8,565
    688
    Only one side is easy, the shaft needs to come out to get at the other one. The shaft is like a nail or a bolt, it has a non-removable head on one end.
     
  7. eight0

    eight0 XS650 Enthusiast

    45
    34
    18
    London
    I'm with you. Ok well I guess I will find out on Tuesday. If it is ok, would you risk putting them in the cleaner with the seal in the other side?
     
  8. 5twins

    5twins XS650 Guru Top Contributor

    18,333
    8,565
    688
    I suppose it would depend on what cleaning solution you have in the ultrasonic cleaner. Use something rubber friendly and it would probably be OK. I don't think the sonic vibrations will hurt it, unless maybe it's hard as a rock from age, lol. That's why I would pull the outers first. Their condition should indicate how the others are. You also have new ones on hand you could compare the old ones to. You'll notice the new ones are very soft. Hold one by the edges between your thumb and finger and pinch it a little, make it oval shaped. You can judge the softness from that. Try that on an old one to see how much harder it's gotten.

    These seals need to be soft because they work on vacuum. It's OK that they fit loose in the carb body and on the shaft. The vacuum generated through the carb bore sucks them in tight and makes the seal - if they're still soft enough.
     
  9. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

  10. eight0

    eight0 XS650 Enthusiast

    45
    34
    18
    London
  11. 5twins

    5twins XS650 Guru Top Contributor

    18,333
    8,565
    688
    They look to be by the part numbers, sizes look right too.
     
  12. eight0

    eight0 XS650 Enthusiast

    45
    34
    18
    London
    I left this out of the carb too long i think. I take it this is toast now.
    20170806_170800.jpg 20170806_170751.jpg 20170806_170730.jpg
     
  13. 5twins

    5twins XS650 Guru Top Contributor

    18,333
    8,565
    688
    Maybe, maybe not. That's in the area that the top seals against the body. Maybe a little red rubber grease spread on it will seal it up once the top is on.
     
  14. retiredgentleman

    retiredgentleman XS650 Guru Top Contributor

    I think they will still work. Put some silicone grease on the diaphragms. I use dielectric grease on mine....................its excellent for all rubber parts.
     
  15. eight0

    eight0 XS650 Enthusiast

    45
    34
    18
    London
    I hope so, it looks like the top of that rim is intact so If i'm careful with it the grease might seal it like you say.
     
  16. eight0

    eight0 XS650 Enthusiast

    45
    34
    18
    London
    SO I did a bit of work on this yesterday.
    Interestingly, the throttle seal on the inside of the carb was fine, a bit hard but not bad, the one on the outside was shot though and had to be cut out with a razor blade. (the picture as after I started going at it with the blade)

    20170808_131651.jpg

    I managed to get the screws out of the first carb no problem. The 8mm screws are a little long but it shouldn't cause an issue.

    20170808_152858.jpg

    Unfortunately I stripped one of the screws on the second carb so will have to attempt to drill it out.

    The ultrasonic cleaner worked a treat through

    20170808_131005.jpg

    20170808_130935.jpg
     

    Attached Files:

  17. robinc

    robinc Member of the 'yellow meter gang' Top Contributor

  18. eight0

    eight0 XS650 Enthusiast

    45
    34
    18
    London
  19. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

  20. eight0

    eight0 XS650 Enthusiast

    45
    34
    18
    London
    I know, I am so annoyed with myself. Sometimes its better to let someone else do these things.
    I have found some carbs for sale on ebay that look like early BS38's. Checking the carb guide I think they are the same as mine... am I right?
     

    Attached Files:

Share This Page