1. Hello Guest. You have limited privileges and you can't "SEARCH" the forums. Please "Log In" or "Sign Up" for additional functionality. Click HERE to proceed.

Stripped spark threads

Discussion in 'XJ Technical Chat' started by TG2, Feb 5, 2019.

  1. TG2

    TG2 New Member

    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Colorado Springs
    So I purchased an 81 xj550, and the spark plug hole thread on one of the cylinders is stripped. I got the plug out but can’t get a new one in. The D8EA is a 12mm and .75 deep but I can’t seem to find any thread tool that will help me. Does anybody have any idea on how to fix this? Need help
     
  2. TG2

    TG2 New Member

    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Colorado Springs
  3. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    10,316
    Likes Received:
    2,827
    Trophy Points:
    113
    Location:
    Great North Woods
  4. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    10,316
    Likes Received:
    2,827
    Trophy Points:
    113
    Location:
    Great North Woods
    you may want to go to auto parts store to get one so you can make sure it will fit inside the fins

    a machine shop could fix it for you
     
  5. Jetfixer

    Jetfixer Well-Known Member

    Messages:
    2,213
    Likes Received:
    918
    Trophy Points:
    113
    Location:
    Nothern Indiana
    Autozone , sells a nice thread chaser , think I paid 12$ very handy tool . Unless threads are completely gone I would try this first.:D
     
    k-moe likes this.
  6. jayrodoh

    jayrodoh YimYam

    Messages:
    1,907
    Likes Received:
    784
    Trophy Points:
    113
    Location:
    Cleveland
    Don’t forget to put heavy grease on any tap/thread chaser you use to catch shavings from going in cylinder.
     
    Jetfixer likes this.
  7. Baker6x6

    Baker6x6 Member

    Messages:
    35
    Likes Received:
    26
    Trophy Points:
    18
    Location:
    Winston Salem, NC
    NO...NO...NO...
    You do NOT want to use any standard tap or thread-chaser for stripped spark plug threads.
    You DO want a "BACK-TAP"... (link)

    This is a thread repair tool that can be inserted into the cylinder, expanded, and then the treads are straightened when you back the tap OUT.
    You do need to use heavy grease to catch any burrs.... that result from straightening the threads.
    [​IMG]
     
  8. k-moe

    k-moe Pie, Bacon, Bourbon. Moderator Premium Member

    Messages:
    17,353
    Likes Received:
    5,449
    Trophy Points:
    113
    Location:
    City of Seven Hills
    Those do have a reputation for occasionally breaking and requiring head removal to remove the broken peices.
    Due care with any tool (this one, or a traditional thread reforming/chasing tool) prevents those sorts of problems though.
     
    hogfiddles likes this.
  9. LarryMc

    LarryMc Active Member

    Messages:
    349
    Likes Received:
    192
    Trophy Points:
    43
    Location:
    Lakewood, WA
    If you don't have enough "meat" left to chase and rethread the damaged plug hole you can use one of the following.
    It provides steel threads and is made specifically for spark plug applications. They are locked in mechanically but red Loctite can also be used for insurance measures.
    Do a search and you'll find numerous videos that walk you through the process.
    Good luck and let us know how everything works out.
    Screenshot_20190205-195815_Chrome.jpg Screenshot_20190205-195957_Google.jpg
    I used one of these on my dirt bike when it blew the plug out while doing hill climbs. I can vouch that these work great and the operation, in my case, did not require removing the head.
     
    Last edited: Feb 5, 2019
    Franz and Chitwood like this.
  10. Chitwood

    Chitwood Well-Known Member

    Messages:
    849
    Likes Received:
    358
    Trophy Points:
    63
    Location:
    Fort Atkinson, Wisconsin
    Have used those save a thread inserts to repair many ford Triton engines that have expelled a spark plug with very good success.
     
    LarryMc likes this.
  11. TG2

    TG2 New Member

    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Colorado Springs
    Okay so I fixed the threads, thanks guys. Now the next problem is the bikes fuel system, for some reason it’s being starved so I don’t know if it is the vacuum line or what but I pulled off the petcock and it didn’t have any lines to it like it should. The PO installed a inline filter as well. This is how it came off the bike
     

    Attached Files:

  12. TG2

    TG2 New Member

    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Colorado Springs
    Is that how these bikes petcocks look?
     
  13. TG2

    TG2 New Member

    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Colorado Springs
    The fuel flows freely in the prime position, but as soon as I connect the fuel line the prime position no longer flows as it should
     
  14. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    10,316
    Likes Received:
    2,827
    Trophy Points:
    113
    Location:
    Great North Woods
    do you have the "tank filter" for that petcock?
    that part is what sets fuel levels and determines when you need to turn to reserve from Fuel (on)

    is there a second nipple on that petcock or just 1?

    if it is a vacuum petcock there should be a hose running from one of the carb manifold ports. there are 4 3 with caps and 1 for hose.
     
  15. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    10,316
    Likes Received:
    2,827
    Trophy Points:
    113
    Location:
    Great North Woods
    some of them. that face plate looks like the one on my 550 seca. 550 maxim has a different look. I do not think the petcocks are year specific. just what they had at the time
     
  16. TG2

    TG2 New Member

    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Colorado Springs
    Yeah it has 2 nipples. One is the fuel line and the other is the vacuum line. There is no in tank filter either which is confusing to me. Would that be a reason the bike is starved ?
     
  17. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    10,316
    Likes Received:
    2,827
    Trophy Points:
    113
    Location:
    Great North Woods
    not having the tank filter would let the larger crud through into the petcock .
    with out it in place you will have no reserve feature but will operate in both fuel or reserve

    remount it on tank do you have a vacuum bleeder ? connect it to the nipple pump and see if gas flows
    or put the vacuum hose on it and suck on the end you should be able to activate the diaphragm in the petcock and see gas flow in the run position

    you could just need a new vacuum hose 4 mm I would search out a complete petcock and replace the one you have just because the tank filter is missing.
     
  18. TG2

    TG2 New Member

    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Colorado Springs
    So I tried everything you just said and the fuel flows nicely on prime when I remove the inline filter however when I place that same filter back onto the tank side hose, the flow stops which is weird since it is not clogged. Is there a possibility of air from the engine and Carb side stopping the fuel from flowing? Also could the lack of airflow be due to the picture below?
     

    Attached Files:

  19. Timbox

    Timbox Well-Known Member

    Messages:
    1,133
    Likes Received:
    341
    Trophy Points:
    83
    Location:
    Wisconsin, Tomah
    Sounds like the fuel bowls are either stuck in the closed "up" position or something is blocking the fuel from going into the carbs. The bowls could be full of fuel already and that is why you don't "see" any flow in the filter. The gas could be so clean you don't see if flowing too.

    Do the carbs have fuel in them? There are drain screws in the bottom outside of carb bowl. If you loosen that, fuel should start to flow our of the drain for each of the carb bowls.
     
  20. TG2

    TG2 New Member

    Messages:
    19
    Likes Received:
    0
    Trophy Points:
    1
    Location:
    Colorado Springs
    I just checked the bowls and they do have fuel in them, so is there any explanation besides the vacuum line that the bike is not getting fuel?
     

Share This Page