The XL600 thread

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

  1. Aaron from Texas

    Aaron from Texas Been here awhile

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    Oddometer:
    491
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    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?
  2. RFVC600R

    RFVC600R SAND EATER

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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
  3. davek181

    davek181 Long timer

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    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.
  4. Schrauberklaus

    Schrauberklaus ***ifyer

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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
  5. Reposado1800

    Reposado1800 Juicy J fan!

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    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.
  6. davek181

    davek181 Long timer

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    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.
  7. RFVC600R

    RFVC600R SAND EATER

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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.
  8. Homerb

    Homerb Been here awhile

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    Jun 24, 2011
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    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.
  9. RFVC600R

    RFVC600R SAND EATER

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    New valve stem seals in, just another step done!
  10. Aaron from Texas

    Aaron from Texas Been here awhile

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    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
  11. JimRidesThis

    JimRidesThis Local celebrity

    Joined:
    Jan 2, 2012
    Oddometer:
    353
    Location:
    Cumbria, UK
    Finally, my XL is on the road!

    Couldn't resist sharing a couple of pics from tonight's shakedown run...

    [​IMG]

    [​IMG]

    Thanks for all the help folks! :D:D:D
  12. Chet Jr

    Chet Jr Adventurer

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    Jun 8, 2011
    Oddometer:
    41
    I'm looking for a shop to rebuild a couple of motors within two months.

    Does anyone have a recent positive experince they can share?

    Thanks
  13. mcma111

    mcma111 Long timer

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  14. RFVC600R

    RFVC600R SAND EATER

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    I have been thinking, I don't have a way to measure the valve springs and if they were (probably are) out of spec I won't be able to afford to replace them. So, should I use the springs from my '83 head with 15K miles or 84' with 28K miles??I want to use the springs from the '83 but I don't know, the old XL ran excellent before the valve seat came loose.:earWhat happens if the springs are out of spec?
  15. brucifer

    brucifer Long timer

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    If the springs are out of spec, it means they have lost some tension. If they lose tension they can lose their ability to close the valve at higher RPM. If they lose their ability to close the valve when necessary, the valve can hit the piston, if the valve hits the piston, you bend a valve and the head comes back off. If that all happens, you will be unhappy. :D
  16. cdiver666

    cdiver666 n00b

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    May 24, 2013
    Oddometer:
    8
    Location:
    Chesapeake, Va
    Hey I picked up a 86 xl600r. Used it offroad only in the Massachusetts state parks while I was waiting for my road test and to get through the Navy red tape. Now it is street legal and I can use it for commuting also.
    [​IMG]
    It has a cobra pipe and XR's only oil temp dipstick.

    I rode it from my apartment back to my house, about a 5 hour ride. It was pretty sketchy on I90 but the wind wasn't too bad after I tightened all the straps on my backpack. My biggest concern was at higher speeds I saw temps of about 320. The way back was a little worse and it was more like 325. When I got back to the apartment I parked it and the next morning it had leaked out some oil. I topped it off and it leaked a bit more out but no longer leaks now it appears. So I rode it to work and on the way back it would not idle without dying, so anytime I gave it the clutch I had to gas it.

    It ran great before, maybe I have to clean the carbs again but I'm worried about the overheating. Think it caused some real damage? I was hoping to ride it this season before overhauling it during the winter.
    thanks guys, been reading the thread, great stuff.
  17. mcma111

    mcma111 Long timer

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    cdiver666,

    You may have overheated the engine and damaged the piston. How low did the oil level get? Where was it leaking the oil from? Going from a good running engine to not wanting to idle is not good.
  18. RFVC600R

    RFVC600R SAND EATER

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    Ok so I'm gonna use the springs from the '83 then. Half the mileage so maybe half the wear?? The piston and valves don't show signs of hitting each other before, I only over revved it couple times :D

    God I wish I had money, I woulda just shipped this lump to MCMA and get the Engine Dynamics treatment and be riding by now with no worries. I'm saving my original head for machine work next time I tear her down.
  19. RFVC600R

    RFVC600R SAND EATER

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    Got my hands on a measuring caliper, Gotta resaerch how to use it then measure all these springs and valves.
  20. RFVC600R

    RFVC600R SAND EATER

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    '83 Valve springs

    outter
    #1 1.465 in
    # 2 1.475 in
    #3 1.465 in
    #4 1.470 in

    Inner
    #1 1.305 in
    #2 1.310in
    #3 1.310 in
    #4 1.312 in

    Gonna go get my book from my bro's garage and compare specs then measure the '84 valve springs. Then I will use the best springs for reassembly