The XL600 thread

Discussion in 'Thumpers' started by Gregster, Jul 6, 2007.

  1. Aaron from Texas

    Aaron from Texas Been here awhile

    Joined:
    May 3, 2010
    Oddometer:
    491
    Location:
    Texas
    I sure hope so.

    I forgot to mention I have a new CDI, coil, stator, and plug boot.

    I ordered everything in "one shot" but last time I checked the PG, it tested within spec, but that was like 3 years ago... Even though this thing hasn't ran in nearly 15y ears, it's like the electronics just rot away...

    I'm gonna replace it tonight and see how things go. Any tips for the right side cover R&R?

    Also... what is the best material used to seal up the airbox boots? Mine look fine, but I'm sure that wouldn't hurt.
  2. Reposado1800

    Reposado1800 Juicy J fan!

    Joined:
    Dec 8, 2006
    Oddometer:
    5,806
    Location:
    5th and Main
    Just lay it over to the left so the oil doesnt drain out. The PG is 2 bolts. I use permatex non hardening sealer on everything, boots, grommets etc. It works good.
    The heat kills all the electrical parts. Running an oil cooler should extend the life though for the new parts.
  3. The Roadie

    The Roadie Adventurer

    Joined:
    Nov 4, 2012
    Oddometer:
    52
    Location:
    Akron, Ohio
    What condition and color is the tank? How much? Also the rims? ...I just recently bought a '82 500r.. so much fun :rofl
  4. Aaron from Texas

    Aaron from Texas Been here awhile

    Joined:
    May 3, 2010
    Oddometer:
    491
    Location:
    Texas
    Well, I got the PG swapped. Made sure my throttle cables were adjusted properly (because of the idle issue), and took off for a spin. The power seems to be back, it's actually surprising me how powerful it is. But it's still lugging around 60-70 mph and the decel pop is still there.

    Occasionally it seems worse than it was before the diaphragm swap and now this odd idle speed issue has started. It doesn't matter how much I close the throttle (and I know the push cable is tight) the engine will just scream on its own...

    Could there be an issue using this new diaphragm with the old spring? Could the new diaphragm be defective?

    I'm at a loss... The only symptoms before the new diaphragm was the decel pop and lugging over 60...

    One other thing I checked was the resistance on the coil. The primary (between the two connections) checked okay, but the resistance between the secondary (connection and boot) was low... This was a new coil I got from Ricky Stator...
  5. Schrauberklaus

    Schrauberklaus ***ifyer

    Joined:
    Aug 25, 2010
    Oddometer:
    398
    Location:
    Phuket ,Thailand

    Hi

    As you swap the diaphragma , dit you make sure that the little O-Ring
    next to the diaphragma is in place ?
    Right way around ? , it has two differnt sides , Flat side goes to the Carb body .
    If your old spring has enough tension to push the pin in the center of the diaphragma against the spring behind the Air cut valve itself then its fine .
    But at idle the low pressure in front of the Carbslide go over a small bore (sealed by the o-ring) to the spring side of the diaphragma and compress the spring so the pin is pulled back and the Aircut valve can close . If the O- Ring leak or is lost you get a leak and the Aircut Valve can never close and the mix at idle is not correct .
  6. RFVC600R

    RFVC600R GOT SAND? NO!

    Joined:
    Dec 16, 2011
    Oddometer:
    3,150
    Location:
    SAND LAND
    Well project has halted.I couldn't get one of the bolts on the side of the cylinder off :puke1 It just stripped when I twisted 10mm wrench. Oh well, going to the machine shop tomorrow anyway.
  7. Aaron from Texas

    Aaron from Texas Been here awhile

    Joined:
    May 3, 2010
    Oddometer:
    491
    Location:
    Texas
    Yes, the new one came with a new o-ring, and I just went ahead and swapped that as well, flat side against the carb body. The old spring was actually longer than the new one...

    Are there any external vacuum lines that control the carbs at all, or is all the vacuum pulled internally? I thought I traced all the lines, and they all seemed to either be breather tubes or drain tubes, so I couldn't see if a cracked line would cause any issues.

    I guess I can pull the carbs again and swap in the "new" spring, but I'm not sure how that would change anything. Again, the new spring is shorter and beehive shaped...
  8. Reposado1800

    Reposado1800 Juicy J fan!

    Joined:
    Dec 8, 2006
    Oddometer:
    5,806
    Location:
    5th and Main
    Maybe an intake manifold leak.
    Check the exhaust doughnut and header copper orings for leaks.
  9. Schrauberklaus

    Schrauberklaus ***ifyer

    Joined:
    Aug 25, 2010
    Oddometer:
    398
    Location:
    Phuket ,Thailand
    External Vacoum lines only if you have the california model carb .
    Maybe its a manifold leak , maybe the Aircut valve is sticky and don't close even when the diaphragma pulls the pin back .
    Dit you test that ?
  10. RFVC600R

    RFVC600R GOT SAND? NO!

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    Dec 16, 2011
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    3,150
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    The new head is in excellent condition:clap The machine guy told me to just wire brush the black shit off and slap it in. Too bad I got to watch the kid today while my wife is at work. I'm getting anxious!

    Edit: The camshaft from the 84' looks trashed, It's blackened on two lobes, can it be saved? not too important though.
  11. Aaron from Texas

    Aaron from Texas Been here awhile

    Joined:
    May 3, 2010
    Oddometer:
    491
    Location:
    Texas
    I just replaced those, and have been tightening them down to spec through various heat cycles...

    I have the Cali model... Vacuum lines EVERYWHERE.

    Gonna check for manifold leaks... How do I test the valve?
  12. RFVC600R

    RFVC600R GOT SAND? NO!

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    Dec 16, 2011
    Oddometer:
    3,150
    Location:
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    Anymore tips before I reassemble? The only problem I see is the tensioner. What about getting the piston back in the cylinder? anything I need to do special or watch out for?? what's a good assembly lubricant?:ear:ear
  13. davek181

    davek181 Been here awhile

    Joined:
    Aug 2, 2007
    Oddometer:
    996
    Location:
    Idaho
    I put the piston into the cylinder while it is off the bike so I can have better control and visual confirmation of ring compression. Then I slide it onto the engine and install the pin and clips. Stuff rages in the open cylinder hole so you don't drop the clips.

    There are several posts online involving the tensioner, Some use zip tyes to hold it in place, others fabricate a tool to go into the hole like the factory one.
  14. Schrauberklaus

    Schrauberklaus ***ifyer

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    Oddometer:
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    Location:
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    Then check that all external hoses are correct connect and without leak .

    Aircut Valve check : remove Diaphragma push the small plate by hand with a small screwdriver , check by eye its moving in and out then test its sealing with a few drops of gasoline
  15. Reposado1800

    Reposado1800 Juicy J fan!

    Joined:
    Dec 8, 2006
    Oddometer:
    5,806
    Location:
    5th and Main
    This might sound weird but I put rings in dry and the gaps all in line. Then after rings are in the jug I swipe oil on the piston skirt. Crazy but it works. Rings break in immediately.
  16. davek181

    davek181 Been here awhile

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    Aug 2, 2007
    Oddometer:
    996
    Location:
    Idaho
    I always assemble dry too. I space the ring end 120 degrees apart. I don't put any oil on anything in the cylinder but the wrist pin, haven't for years. Never had a comeback for oil burning of seizure, in fact they usually have great compression and less than 5% leakdown after breaking in.

    OH, I don't hone either, haven't honed a hole since 1980 when Honda told me it was unnecessary.
  17. RFVC600R

    RFVC600R GOT SAND? NO!

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    Location:
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    Well.... I just wanna ask if there is a trick to getting the valve keepers in. It's just a little tedious :eek1 I'm changing the valve seals right now so I don't have a smoking engine when I run it later.
  18. Homerb

    Homerb Been here awhile

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    Jun 24, 2011
    Oddometer:
    481
    Location:
    Toukley NSW Australia
    Ive just done a 16 valve head on my wifes car. A thin screwdriver with a dab of grease for the keeper to stick to worked well for me. Make sure theres a bit of grease on the inside of the keeper so it sticks to the valve stem.
    A slightly magnetized screwdriver helps too.
  19. RFVC600R

    RFVC600R GOT SAND? NO!

    Joined:
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    Location:
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    New valve stem seals in, just another step done!
  20. Aaron from Texas

    Aaron from Texas Been here awhile

    Joined:
    May 3, 2010
    Oddometer:
    491
    Location:
    Texas
    Visually, the vacuum lines look great. Guess I'll have to take the carbs out again... dammit. I might try that other spring too.

    Something certainly went awry when I did the diaphram. Certainly. The bike was running pretty good beforehand, and I never got that odd misfire or erratic idle...


    Another thing I've been reading about is disabling the air cut off valve entirely and richening the idle circuit so the valve is no longer needed... Check these links out...

    http://deuceswild.yuku.com/topic/1691

    http://www.motorcycleproject.com/motorcycle/text/keihin_idle_circuits_white_paper.swf