1. Some members were not receiving emails sent from XJbikes.com. For example: "Forgot your password?" function to reset your password would not send email to some members. I believe this has been resolved now. Please use "Contact Us" form (see page footer link) if you still have email issues. SnoSheriff

    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.

Sparkplugs

Discussion in 'XJ Technical Chat' started by Big swede, Oct 18, 2015.

  1. Big swede

    Big swede Active Member

    Messages:
    184
    Likes Received:
    51
    Trophy Points:
    28
    Location:
    Gothenburg,Sweden
    Do you know wich sparkplugs i should use on my xj750? There is bp7es (ngk) now, but i'm not sure if it's right or if i should have resistorplugs, would be good to know before i by new ones...
     
    Last edited: Oct 18, 2015
    Big swede, Oct 18, 2015
    #1
  2. MN-Maxims

    MN-Maxims St. Paul Minnesota

    Messages:
    3,067
    Likes Received:
    114
    Trophy Points:
    63
    Location:
    Saint Paul, MN
    BP7ES are the correct ones if you have resistor caps on your plug wires.
     
    MN-Maxims, Oct 18, 2015
    #2
  3. Big swede

    Big swede Active Member

    Messages:
    184
    Likes Received:
    51
    Trophy Points:
    28
    Location:
    Gothenburg,Sweden
    Ok, then i'll by the same ones. Thank you!
     
    Big swede, Oct 18, 2015
    #3
  4. rocs82650

    rocs82650 Well-Known Member

    Messages:
    2,663
    Likes Received:
    356
    Trophy Points:
    83
    Location:
    Middle Tennessee
    The plugs should torque at 14.5 ft lbs. Have you ohmed out the caps to make certain the resistors are good?
    Two of the ht caps have screw in resistor holders. Make sure they are snug. Hope this helps.

    Gary H.
     
    rocs82650, Oct 18, 2015
    #4
  5. MN-Maxims

    MN-Maxims St. Paul Minnesota

    Messages:
    3,067
    Likes Received:
    114
    Trophy Points:
    63
    Location:
    Saint Paul, MN
    He could get non resistor caps then go with resistor plugs also if his caps are junk.
    Depends on what's available where he is at.
     
    MN-Maxims, Oct 18, 2015
    #5
  6. rocs82650

    rocs82650 Well-Known Member

    Messages:
    2,663
    Likes Received:
    356
    Trophy Points:
    83
    Location:
    Middle Tennessee
    True. Does Len ship to Sweden?

    Gary H.
     
    rocs82650, Oct 18, 2015
    #6
  7. MN-Maxims

    MN-Maxims St. Paul Minnesota

    Messages:
    3,067
    Likes Received:
    114
    Trophy Points:
    63
    Location:
    Saint Paul, MN
    He might but money conversion and time to get there would be considerations.
     
    MN-Maxims, Oct 18, 2015
    #7
  8. rocs82650

    rocs82650 Well-Known Member

    Messages:
    2,663
    Likes Received:
    356
    Trophy Points:
    83
    Location:
    Middle Tennessee
    Also true.

    Gary H.
     
    rocs82650, Oct 18, 2015
    #8
  9. Big swede

    Big swede Active Member

    Messages:
    184
    Likes Received:
    51
    Trophy Points:
    28
    Location:
    Gothenburg,Sweden
    No not yet, they should be 10 kohm right?
    So they're not all the same?
     
    Big swede, Oct 18, 2015
    #9
  10. Big swede

    Big swede Active Member

    Messages:
    184
    Likes Received:
    51
    Trophy Points:
    28
    Location:
    Gothenburg,Sweden
    It shouldn't be a problem getting the right stuff over here....just want to make sure what is right...
     
    Big swede, Oct 18, 2015
    #10
  11. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,861
    Trophy Points:
    113
    Location:
    Great North Woods
    XJ750 air-cooled models:
    Spark plug caps    :
    1981-83 models: 5K +/- 20% = 4,000 to 6,000 ohms per cap acceptable range
    1984 RL models: 10K +/- 20% = 8,000 to 12,000 ohms per cap acceptable range

    Spark plugs:
    0 ohms per plug
     
    XJ550H, Oct 18, 2015
    #11
  12. k-moe

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

    Messages:
    19,647
    Likes Received:
    6,756
    Trophy Points:
    113
    Location:
    The City of Seven Hills
    That depends on which XJ you have.
     
    k-moe, Oct 18, 2015
    #12
  13. Big swede

    Big swede Active Member

    Messages:
    184
    Likes Received:
    51
    Trophy Points:
    28
    Location:
    Gothenburg,Sweden
    It's a 83 750 seca (aircooled).
    1: 5,56 kohm
    2: 6,21
    3: 5,82
    4: 5,93
    So number 2 is a little to high then.
    Always nonresistive plugs?
     
    Big swede, Oct 18, 2015
    #13
  14. XJ550H

    XJ550H Well-Known Member Premium Member

    Messages:
    13,199
    Likes Received:
    3,861
    Trophy Points:
    113
    Location:
    Great North Woods
    you can run resistive plugs instead of resistive caps then you will always be refreshing the resistors when you change out the plugs.
     
    XJ550H, Oct 18, 2015
    #14
  15. Big swede

    Big swede Active Member

    Messages:
    184
    Likes Received:
    51
    Trophy Points:
    28
    Location:
    Gothenburg,Sweden
    Sounds like a good idea, i might do so.
     
    Big swede, Oct 18, 2015
    #15
  16. k-moe

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

    Messages:
    19,647
    Likes Received:
    6,756
    Trophy Points:
    113
    Location:
    The City of Seven Hills
    #2 is a little high, but not too high. The later 750's and 700's had 10K ohm caps.
     
    k-moe, Oct 18, 2015
    #16
  17. cgutz

    cgutz Well-Known Member

    Messages:
    1,203
    Likes Received:
    719
    Trophy Points:
    113
    Location:
    SE South Dakota
    My xj550 was running poorly this summer. I thought it was a carbeurator issue. Turns out one of the 10kohm caps had infinite resistance. Just this weekend replaced with an NGK 5kohm cap and 5kohm resistor spark plug since 10kohm caps unobtanium.

    Bike is running better than in years. Didn't want to stop driving it today. No carb issues after all.

    Ordered the parts to convert the other cylinders over to same setup for consistency.
     
    cgutz, Oct 18, 2015
    #17
  18. k-moe

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

    Messages:
    19,647
    Likes Received:
    6,756
    Trophy Points:
    113
    Location:
    The City of Seven Hills
    k-moe, Oct 18, 2015
    #18
  19. cgutz

    cgutz Well-Known Member

    Messages:
    1,203
    Likes Received:
    719
    Trophy Points:
    113
    Location:
    SE South Dakota
    Chacal does have stock caps, but I wanted to get local it get it back on the road and not wait for shipping.


    The link you provided to NGK plug is for a 14mm cap. I believe the proper cap for outside cylinders would be LD10e. Inside cylinders would be VD10e I believe. I used YB05e and a resister spark plug.
     
    Last edited: Oct 19, 2015
    cgutz, Oct 19, 2015
    #19
  20. k-moe

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

    Messages:
    19,647
    Likes Received:
    6,756
    Trophy Points:
    113
    Location:
    The City of Seven Hills
    My point was that 10 ohm resistor caps are available in many sizes and shapes.
    Your comment about them being unobtanium will be read by someone else, and might make them think that it's not possible to get them.
     
    k-moe, Oct 19, 2015
    #20
  21. chacal

    chacal Moderator Moderator Supporting Vendor Premium Member

    Messages:
    9,170
    Likes Received:
    1,977
    Trophy Points:
    113
    Location:
    The room where it happened
    You can use "14mm" plug caps on 12mm plugs as long as the plugs have the hour-glass shaped stud NUT on them:

    HCP13192 Aftermarket NGK SPARK PLUG CAP, 10K ohms, short 90-degree angled boot, for 14mm "B" plugs with a threaded stud on top. Suitable replacement for the stock plug caps on the outer (#1 and #4) cylinders on XJ550 and 1984-85 FJ600 models, and on all four cylinders on 1992-98 XJ600 Seca II models.. Slightly taller and deeper than original caps, they will fit and perform properly, and the 120-degree angled plug wire end offers some additional clearance as compared to the stock 90-degree right-angled caps. NOTE: the use of these plugs caps requires the installation of our HCP13518 adapter nuts onto the threaded stud at the top of the spark plug. Each:


    HCP13518 Aftermarket spark plug threaded top stud ADAPTER NUT, hour-glass shaped aluminum nut attaches to the threaded stud on the top of the spark plug. Needed when using plug caps designed for 14mm spark plugs on any 12mm "D" series plugs. Use 1 per plug. Can be re-used almost indefinitely from one spark plug to the next. Each
     
    chacal, Oct 19, 2015
    #21
  22. cgutz

    cgutz Well-Known Member

    Messages:
    1,203
    Likes Received:
    719
    Trophy Points:
    113
    Location:
    SE South Dakota
    Update- after switching my original caps all over to 5kohm with 5kohm spark plugs, the bike is running even better. Although 3 caps read in spec (10kom), changing the 32 year caps made a big difference. (And it wasn't just because of new sparkplugs, they had just been replaced).

    Considering the low cost of these NGK caps, I highly recommend updating to new ones even if your original caps read in spec. I wonder if the low current of the ohm meter gives false impression they will perform well at high voltage.
     
    cgutz, Oct 24, 2015
    #22
  23. MN-Maxims

    MN-Maxims St. Paul Minnesota

    Messages:
    3,067
    Likes Received:
    114
    Trophy Points:
    63
    Location:
    Saint Paul, MN
    So did you get the ones from xj4ever? I should do the same for my dyna coils
     
    MN-Maxims, Oct 24, 2015
    #23
  24. cgutz

    cgutz Well-Known Member

    Messages:
    1,203
    Likes Received:
    719
    Trophy Points:
    113
    Location:
    SE South Dakota
    Local place had NGK 5kohm caps and 5kohm NGK sparkplugs. I believe XJ4ever also has them. PART_1445799410992_20151024_110929.jpg
     
    cgutz, Oct 25, 2015
    #24
    rocs82650 likes this.

Share This Page