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Oldie but a goodie

Discussion in 'The Garage' started by Yamadogrick, Oct 16, 2020 at 4:26 PM.

  1. Yamadogrick

    Yamadogrick XS650 New Member

    Refreshing a long neglected 77 XS top end and an age-old question comes to mind: what sealers (if any) to use on both the base and head gaskets? They are new Athenas. Gut tells me to go ahead with a thin smear of Permatex aircraft for the base, and nothing (except maybe around the chain tunnel) on the head gasket. I have heard though that the newer Athena base gaskets are chemically treated and require nothing but clean surfaces to seal. Any preferences out there? TIA!
     
  2. thuban

    thuban Horse Scratcher XS650.com Supporter Top Contributor

    I sprayed my head gasket with Coppercoat. Also sprayed the base gasket. But the base gasket walked out a bit. I was afraid it would walk out completely in places but Jim's did the same thing and finally stopped. I thought that sucked! But, it did stop and it doesn't leak after a year of running. Just make sure to use copper or brass washers under the top outer head nuts and do a retorque. Permatex will do it. But I bet good and clean will also work. ( I had to take my head back off after a few miles due to me being dumber than a hammer and the head gasket was stuck in most places.
     
    GLJ and gggGary like this.
  3. Yamadogrick

    Yamadogrick XS650 New Member

    Thanks thuban, i think I'm just going to use a very thin smear of Permatex on the lower side of the base, and install the head gasket as is, on super clean surfaces, I have new copper head washers for the outboard top nuts. after five or six 650s this is the first motor I've torn down. Did an SR 500 some time ago but that's a little simpler machine :) Appreciate your input.
     
  4. thuban

    thuban Horse Scratcher XS650.com Supporter Top Contributor

  5. GLJ

    GLJ Never go faster than your guardian angle can fly. Top Contributor

    I use red grease on both sides of the base gasket and Coppercoat on the head gasket. Both engines I've done have been leak free. I prefer red grease to gasket sealer. If you ever have to take it apart in the future clean up will be much easier. If the surfaces are flat, clean with no deep gouges the gasket will seal. The reason I use Coppercoat is for heat transfer not sealing.
     
    gggGary likes this.
  6. thuban

    thuban Horse Scratcher XS650.com Supporter Top Contributor

    My experience with the creeping base gasket..I wouldn't go near the grease! If you rub oil on Athena gaskets it turns to snot!
     
  7. GLJ

    GLJ Never go faster than your guardian angle can fly. Top Contributor

    I've not seen any gasket creep. But as has been said. Results do vary.
     
    gggGary and thuban like this.
  8. motormike

    motormike XS650 Junkie XS650.com Supporter Top Contributor

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    Yamabond on base gaskets.. I popsicle stick the O rings into the grooves.... head gaskets.. dry... So far.. cross my pinkies.. no problems...
     
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  9. thuban

    thuban Horse Scratcher XS650.com Supporter Top Contributor

    :laugh2: GLJ, I was looking for the damn Pix but the whiskey glass is in the way! But it spooched ( Technical term) out 1/8 inch in places. (Like that 10mm socket, can't ever find it when you want it.)
     
    gggGary likes this.
  10. thuban

    thuban Horse Scratcher XS650.com Supporter Top Contributor

    Motormike, I do like that Yamabond! ( I got a different use for popsickle sticks.) What?
     
    gggGary likes this.
  11. timbeck

    timbeck XS650 Junkie XS650.com Supporter

  12. thuban

    thuban Horse Scratcher XS650.com Supporter Top Contributor

    Well, popsickle sticks...Viagra just gives me a headache. That shit don't work! Ole lady says, "I wonder what would happen If I take one?" I said, "Well, first I think your missing a few biological specifications but I'm sure I can do a work around and have you come up with something!" :geek:
     
  13. xjwmx

    xjwmx It's just the unknown. Top Contributor

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    When I was researching mine, I came across a site that was talking about our engine that said don't use sealer there. "I don't care if the person who says to use sealer says he rode with Che Guevara." That was too good to ignore, so I didn't use any and haven't had any problems, nothing creeping or leaking or blowing out in maybe 5,000 mi. I had NOS gaskets they sold on ebay for awhile made by SCM.
     
    gggGary likes this.
  14. Jim

    Jim Beyond the edge is the unknown. Here be Dragons XS650.com Supporter Top Contributor

    I use Permatex Aviation sealant on the base and copper spray sealant on the head. In my mind, using it is a little extra insurance against leaks. You can not use it and probably be fine. Using it just ups the odds it won't leak.... and there's no real down side to using it.
    The copper helps heat transfer. With air cooling, any help with heat removal is worth the five or ten bucks spent.
     
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  15. 5twins

    5twins XS650 Guru Top Contributor

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    My base gasket crept out. It was the Athena one, maybe that's why. I did use some sealer on it, some sort of liquid Permatex my dealer recommended. I don't know if that contributed to the "creep" or not. I've scored some N.O.S. originals off eBay now for future use. I'll probably install them dry, save for the sealer already on them from the factory. It's not much, just some across the front and rear of the cam chain tunnel .....

    [​IMG]
     
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  16. thuban

    thuban Horse Scratcher XS650.com Supporter Top Contributor

    This is a lot of creep... You can see how the gasket cracked at the corner there. I trimmed off the "spooch" and it's been holding. Makes me wonder what happened around the timing chain tunnel? . I hope I don't have to find out anytime soon! :)
    gasket fail.jpg
     
  17. GLJ

    GLJ Never go faster than your guardian angle can fly. Top Contributor

    I'm thinking you didn't hold your mouth right when assembling.o_O
    upload_2020-10-18_11-8-55.png

    upload_2020-10-18_11-9-34.png
     
    timbeck likes this.
  18. 5twins

    5twins XS650 Guru Top Contributor

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    That may not be as much "creep" as you think. The Athena gasket is a bit oversized to begin with, so it will stick out all around some. Your front and side may be as it was installed, but the rear definitely crept out some. Here's mine, and you can see by the dark colored gasket sealer I applied where it started out and where it crept out to .....

    [​IMG]

    [​IMG]

    [​IMG]

    Thankfully, it stopped at this point, never going any farther, and has never leaked. Eventually I went around and just trimmed the excess off .....

    [​IMG]
     
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  19. thuban

    thuban Horse Scratcher XS650.com Supporter Top Contributor

    Not holding my mouth right...been guilty of that before. :) It's possible, but I attributed this problem to the gasket make. Your top pix looks like Athena but the bottom one doesn't. Not much you can do, just lower the jugs down, assemble and torque. Then the gasket starts walking out from under the jugs and in a matter of days while your getting the engine in and all the other stuff, it looks like that. I did a second retorque at 200 miles just because of that. That's when Jim told me he had one do the same thing and it finally stopped and didn't leak. As an aside, I thought the base gasket was too thick for that area to start with, just my 2 cents. But that damn gasket plays with your piston to head clearance, does it not?

    I don't think Cometic makes a base gasket but If I run across one, I'm gona snag it for the future.
     
    timbeck likes this.
  20. thuban

    thuban Horse Scratcher XS650.com Supporter Top Contributor

    5twins, No the gasket was pretty close to the right size on installation. I just thought it was thick! Man, you did have some creep! WOW, that's nuts! I can see where the gasket was oversized by the sealant. Do you remember what kind of sealant you used?
     

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