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  1. #1
    Hooligan
    Join Date
    Dec 2012
    Location
    St Charles, MO

    ‘80 Kz1000LTD - Excessive smoking

    I’m working on a ‘80 Kz1000B that’s been bored to 1105cc (73mm). I do not know the complete history of the bike but it smokes like a freight train immediately on start-up and pretty much continues smoking heavily until I turn it off. The owner already replaced the valve seals with viton ones (they’re blue). Anyways, #3&4 are the worst offenders as evidence by extremely oily exhaust ports. I checked compression on a cold engine and measured 145-160psi for all four cylinders.

    I went ahead and removed the cylinder head and replaced all the valve seals with another new set of viton ones. I used white lithium grease and a valve seal installer for them. Then when reinserting the valves, I used more white lithium on the stem tips and slowly pushed them in while rotating back and forth.

    I removed the cylinder block as it moved when I removed the head and I didn’t want the base gasket to leak. I installed a new gasket after thoroughly cleaning the case and block surfaces. The rings were not indexed at all so I clocked the rings’ gaps. I filled the o-ring groove in the block with black RTV and let it fully cure over a day or two, went back and trimmed the RTV flush with the block. I bought and installed a Cometic MLS 73mm bore head gasket as the owner used a OEM gasket with a 70mm bore. Before installing the head gasket, I ran a very small bead of black RTV sealant on top of what I trimmed to seal the cam chain tunnel.

    Got it all back together, and it smokes exactly the same as before. The inside of the exhaust is VERY oily. I went ahead and checked compression on #4 after the engine warmed up. It registered 180psi.

    Any suggestions? I’m at a complete loss. The only other things I think it could be is a worn/loose valve guide or maybe the ring end gaps are incorrect.

    Any help would be greatly appreciated.

    Later, Doug



  2. #2
    Hooligan
    Join Date
    Feb 2015
    Location
    San Antonio, Texas

    Re: ‘80 Kz1000LTD - Excessive smoking

    My first guess is EPA stuff, since you ruled out bad compression and have oily exhaust ports. That sounds like what my ZRX motor was doing before I replaced the spark plug seals and installed no-flos to plug the oil holes.

    Side note, it looks like a badass burnout on your lift in the top picture.
    Lesson learned: Squash the cat.
    -JD

  3. #3
    Hooligan
    Join Date
    Dec 2012
    Location
    St Charles, MO

    Re: ‘80 Kz1000LTD - Excessive smoking

    Quote Originally Posted by jrockit View Post
    My first guess is EPA stuff, since you ruled out bad compression and have oily exhaust ports. That sounds like what my ZRX motor was doing before I replaced the spark plug seals and installed no-flos to plug the oil holes.

    Side note, it looks like a badass burnout on your lift in the top picture.
    I forgot to mention, I tapped and inserted 1/8npt plugs into each smog port when I had the valves out.


    And I wish the smoke was only from doing a burnout.

    Later, Doug

  4. #4
    BadAss Hooligan
    Join Date
    Aug 2008
    Location
    oakland county michigan

    Re: ‘80 Kz1000LTD - Excessive smoking

    Did you check the piston/cylinder clearance. How does the crosshatch in the cylinders look?

  5. #5
    Hooligan
    Join Date
    Mar 2002
    Location
    Lincoln Nebr.

    Re: ‘80 Kz1000LTD - Excessive smoking

    Quote Originally Posted by compressor59 View Post
    Did you check the piston/cylinder clearance. How does the crosshatch in the cylinders look?
    Also there are 2 1105 kits. One that came with new sleeves and one without.
    I had one without and it smoked some when hot and I had an oil cooler.


    .
    GREEN is always the fastest

    ZRXOA #3823

  6. #6
    Hooligan
    Join Date
    Dec 2012
    Location
    St Charles, MO

    Re: ‘80 Kz1000LTD - Excessive smoking

    Quote Originally Posted by Nebr_Rex View Post
    Also there are 2 1105 kits. One that came with new sleeves and one without.
    I had one without and it smoked some when hot and I had an oil cooler.


    .
    I assume this kit did not include the sleeves as there was very little chamfer, if any, at the bottom of the sleeves. (Made reinstalling the cylinder a bit of a challenge.)

    I did not check piston OD to bore clearance. One thing that does bother me now that I think about it is I could rotate the pistons in the bores CW and CCW ever so slightly. Wonder if that could be part of it somehow?

    Later, Doug

  7. #7
    BadAss Hooligan
    Join Date
    Sep 2003
    Location
    College Station, TX

    Re: ‘80 Kz1000LTD - Excessive smoking

    Check ring gap? Maybe stock oil ring on oversized piston?

  8. #8
    BadAss Hooligan
    Join Date
    Nov 2006
    Location
    mi.

    Re: ‘80 Kz1000LTD - Excessive smoking

    Quote Originally Posted by Streetfighterkz View Post
    I assume this kit did not include the sleeves as there was very little chamfer, if any, at the bottom of the sleeves. (Made reinstalling the cylinder a bit of a challenge.)

    I did not check piston OD to bore clearance. One thing that does bother me now that I think about it is I could rotate the pistons in the bores CW and CCW ever so slightly. Wonder if that could be part of it somehow?

    Later, Doug
    When could u rotate pistons?.check head for cracks.

  9. #9
    Weirdly Peculiar
    Join Date
    Apr 2008
    Location
    Where am I?

    Re: ‘80 Kz1000LTD - Excessive smoking

    Do a leakdown test on each cylinder to determine ring\cylinder and valve\valve seat condition. Do this test (and the compression test) with the engine at operating temperature. It could be the valve seals were the issue, you fixed it and you just have to be patient while all the oil burns out of the exhaust system. The cylinder block moving on the crankcase doesn't seem correct as most cylinder blocks are located by the cylinder sleeves and\or a couple of dowels, find out why it's moving. The pistons rotating in the bore, if they are on the con rods indicates an issue with the piston pin bores, the con rod small end and\or the piston pins, check that out.

    Basically this engine seems to need a complete going through by someone with knowledge and tools to determine the issues.
    Last edited by BASpro; 12-30-2019 at 02:11 AM.
    2000 Green, 1109, Mikuni 38mm TMR-MJN's, Yosh pipe, ZX-11 cams, Pods, ZX-11 Ignitor, Kwick Kill, Tealdo Stick Coils, Wyn's Sprocket Cover, Ted's Battery Out, MonkeyPincher Rack

    2010 Concours 14 ABS Ball Coddler "The Velvet Missle", 151 HP, lots 'o mods

    "A man's got to know his limitations" Dirty Harry

    He who is right all the time is never always right.

  10. #10
    Hooligan
    Join Date
    Sep 2017
    Location
    Belgium

    Re: ‘80 Kz1000LTD - Excessive smoking

    I suspect the rods that hold the cyl head/cyl to the carter..
    I had the same problem with my z1000J in the 80's
    I bought a second hand one that (unknown by me) had been opend a few times , seems like the rods get "streched out" each time you assemble,
    and torque it up . It is ok if the engine is cold en you measure everything up..
    bun when started the pressure in the combustion chambre forces the cyl head up cos the rods get "lame" after a few assembly's
    so the cyl head oil gets in the chambre and then burns up...replace the connecting rods with NEW ones (def no second hand..) torque up and see
    If that was the problem..
    It is not such a big cost for 8 or 10 (I don't remember how many) rods to replace then for example new pistons /hone job and still not be sure..
    cheers
    Peter

  11. #11
    Hooligan
    Join Date
    Dec 2012
    Location
    St Charles, MO

    Re: ‘80 Kz1000LTD - Excessive smoking

    Quote Originally Posted by ninja11zx View Post
    When could u rotate pistons?.check head for cracks.
    I was able to rotate the #4 piston when the head was off and the piston at TDC. I didn’t check the others.

    Quote Originally Posted by BASpro View Post
    The cylinder block moving on the crankcase doesn't seem correct as most cylinder blocks are located by the cylinder sleeves and\or a couple of dowels, find out why it's moving. The pistons rotating in the bore, if they are on the con rods indicates an issue with the piston pin bores, the con rod small end and\or the piston pins, check that out.
    The dowel pins were/are there. The cylinder only moved upwards breaking the seal with the gasket and upper case. I pulled it to replace the base gasket to prevent any leakage that could have occurred due to that.

    I’ll go ahead do another compression check with the engine up to temp and get a leak-down tester.

    I’ll also look into new cylinder studs as the top end has been apart at least twice: once for the bore job and once when I pulled it.

    I appreciate the help.

    Later, Doug

  12. #12
    Weirdly Peculiar
    Join Date
    Apr 2008
    Location
    Where am I?

    Re: ‘80 Kz1000LTD - Excessive smoking

    "The dowel pins were/are there. The cylinder only moved upwards breaking the seal with the gasket and upper case. I pulled it to replace the base gasket to prevent any leakage that could have occurred due to that."

    Roger that.

    I'll repeat my comment about you perhaps fixing the problem by replacing the valve stem seals and blocking the air passages, and the exhaust system needing time to burn out all the oil. I fouled a plug in my ZRX and in the time it took to get out my infrared thermometer, check the exhaust pipe temps it pumped enough oil into the Kerker exhaust system to create a puddle on the floor under the head pipe\collector junction. Once I replaced the spark plugs it started up fine and smoked for 20 minutes or so.

    The rotating piston is a worry though. This appears to be a drag bike(?) so perhaps this engine has seen nothing but full throttle passes, do you know how many runs on the engine?

    The compression numbers are pretty normal.
    2000 Green, 1109, Mikuni 38mm TMR-MJN's, Yosh pipe, ZX-11 cams, Pods, ZX-11 Ignitor, Kwick Kill, Tealdo Stick Coils, Wyn's Sprocket Cover, Ted's Battery Out, MonkeyPincher Rack

    2010 Concours 14 ABS Ball Coddler "The Velvet Missle", 151 HP, lots 'o mods

    "A man's got to know his limitations" Dirty Harry

    He who is right all the time is never always right.

  13. #13
    BadAss Hooligan
    Join Date
    Nov 2006
    Location
    mi.

    Re: ‘80 Kz1000LTD - Excessive smoking

    piston should not rotate at all if on the rod and in the bore.

  14. #14
    BadAss Hooligan
    Join Date
    Aug 2007
    Location
    New Braunfels, Texas

    Re: ‘80 Kz1000LTD - Excessive smoking

    I had this on my ZRX. The nikisil coating had failed. I suspect something similar. The oil control ring is unable to work properly. Bore problem or ring problem.

    Mine looked like a mosquito fogged in operation. The old thread on it is gone. Replaced the cylinder. No problem since.
    ZRXOA 8377
    '01 Green Machine with some Bling
    '00 RC51
    '83 GPz 550-- Number 4.
    93 Ninja 1100



    For those who understand, no explanation is necessary.
    For those who will not try, no explanation is possible


  15. #15
    Hooligan
    Join Date
    Dec 2012
    Location
    St Charles, MO

    Re: ‘80 Kz1000LTD - Excessive smoking

    I swapped on a spare dry exhaust I had so as to rule out the oily header. Still excessive smoking so I ordered up a Jeg’s leakdown tester as I wanted a better option than an inexpensive Chinese one. I got the leak-down tester yesterday and went to work last night. I only tested #4 with a cold engine which I know isn’t the most accurate method. I set supply pressure to 90psi and set #4 at TDC on the compression stroke. Right gauge read a little over 86psi so about 4% leak down. I figured leak down was probably going to be ok as compression numbers were close to normal. I wanted to test, as previously suggested as it’s non-invasive.

    I did notice as I was rolling over the engine to find TDC the exhaust valve looked wet with oil when looking down through the spark plug hole. I’m guessing there might be a crack or something near the valve guide. Two sets of new valve seals shouldn’t leak...

    Later, Doug

  16. #16
    Devils’ Advocate
    Join Date
    Aug 2001
    Location
    Large and Prickley

    Re: ‘80 Kz1000LTD - Excessive smoking

    Viton valve seals are boarderline junk, but with high lift cams are needed....unless....you shorten the valve guides to get clearance between the tops of the stock seals and the keeper/collets.

    ooooooooooooo

    WARNING: ELS Products MAY CONTAIN, or be Made With, Patented Parts, Tools, Components and/or Apparati. Manufacturing Facility DOES Contain Nuts.

    PayPal to: Pete@Hyper-Formance.com
    www.ExpensiveLightweightStuff.com
    Pete Aronson
    315 West Elliot Road
    Suites 107-487
    Tempe, AZ 85284
    602-397-4869.

  17. #17
    Hooligan
    Join Date
    Dec 2012
    Location
    St Charles, MO

    Re: ‘80 Kz1000LTD - Excessive smoking

    This bike has stock cams and an unported head.

    I have a friend that may take the head and have inspected by his machine shop. They’ll clean the gunk out of the ports and give it a look-over.

    Later, Doug

  18. #18
    Devils’ Advocate
    Join Date
    Aug 2001
    Location
    Large and Prickley

    Re: ‘80 Kz1000LTD - Excessive smoking

    Viton seals aren't needed then. Put stockers on.

    ooooooooooooo

    WARNING: ELS Products MAY CONTAIN, or be Made With, Patented Parts, Tools, Components and/or Apparati. Manufacturing Facility DOES Contain Nuts.

    PayPal to: Pete@Hyper-Formance.com
    www.ExpensiveLightweightStuff.com
    Pete Aronson
    315 West Elliot Road
    Suites 107-487
    Tempe, AZ 85284
    602-397-4869.


 

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