Could it be Foul?

Discussion in 'Sportster Models' started by JohnnyBiker2, Jul 25, 2010.

  1. JohnnyBiker2

    JohnnyBiker2 Member

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    Ok, a while back I had some nasty vibration coming up through my tank. I found the culprit, it was loose tank mounts in the back. I took the tank off, put some loctite on, and the vibration went away. Now I have the vibration back. I took the the plugs out to check them. I thought that the front one looked a little black, but the rear plug looked great.

    Would a fouled plug cause this vibration, or do you think that I need to take the tank off again and check the tank mounts?
     
  2. Scrappy

    Scrappy Active Member

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    motor mounts? check condition and torque. then tank? Is it running ok? if so i wouldn't think it would be a plug.
     
  3. JohnnyBiker2

    JohnnyBiker2 Member

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    You know, I did not check the motor mounts this time. When I originally had the vibration issue I did check them and they were good. I think that I have only 20 miles on it since the first vibe issue, School started for me so Ihave been busy.
     
  4. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    evo sportsers being solid mounted engine do transmit a fair bit of vibration throughout the whole bike
    if the tank is vibrating more than it previously did then id re check the tank mounts to start with

    Brian
     
  5. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    As Fin_676 said, sometimes you have to resign yourself to a fact, solid mounted engine means vibration translates everywhere...and the thing is to to do a fastener/torque wrench check over the whole bike, starting from the source engine mounts, exhaust system mounts, tank and "underneath".

    And my question would be...did this vibration/noise happen recently, sometimes the last service may have disturbed something, be it bad gas to hitting something you were not aware of and damage occurred underneath that is not obvious. That "Potato-Potato" lope we HD riders know and love means the inherent unbalance will shake things loose, if fasteners do not have proper Loctite on the threads, and loose items will hammer themselves up.
     
  6. JohnnyBiker2

    JohnnyBiker2 Member

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    I had a vibration that was caused by the fact that I DID NOT use locktite on the tank mounts when I first installed the tank. I found that problem, put loctite on them, and the problem went away, no more vibration from 60 mph on. As I had said, I have only been able to put about 20 miles on because of school. I have this nagging feeling that the issue is just my plugs, or at worst, my coil is starting to fail. I still have the set of wires that came with the bike when I bought it, so there are a few different possibilities for me to try.
     
  7. Jack Klarich

    Jack Klarich Expert Member

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    If in doubt throw a set of plugs and wires on it it cant hurt:s
     
  8. skull1369

    skull1369 New Member

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    I've had simular problem recently. Both front mounting bolts and rear became loose. added extra washers for tighter fit. rear nut was lost on road. I think my problem is for holding at constant high rpm. mine slightly built ironhead with four speed though. fouling wont cause that kind of vibration,will loosen aircleaner bolts,cause tach cable to break if solid kind(you shouldnt) but wont vib tank. If you have after market tank check if bolts are sloppy in holes,may have to put rubber grommets in holes to tighten up.
     
  9. JohnnyBiker2

    JohnnyBiker2 Member

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    Believe it or not, I changed the plugs and that took care of the problem that I was having. What I did was I took both plugs out, the front one was really black, like there was a real rich condition, the rear one was gray, like it should be. After that I hooked the front one back up to the wire and rested it against the head. I hit the started so I could observe the spark. the front one, before I cleaned it, gave an orangish spark. After I cleaned it, it gave a blue one like it is supposed to. I did this to both plugs and rotated them to see if I got a weaker spark from wire to wire.

    the bike is running awesome again, and I do not think that I am going to run the type of plugs that I was. i went back to the HD plugs.:D

    Yes I have an AM tank and it is already rubber mounted. I had a slight issue if that once before and got that taken care of, everything is tight. I also checked the motor mounts and mine are solid. High RPM's are fun though aren't they?
     
    Last edited by a moderator: Jul 27, 2010