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3LN Plugs

Discussion in 'Yamaha 250cc In-Line 4's' started by robustus0007, Jan 19, 2011.

  1. robustus0007

    robustus0007 New Member

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    Hi there,

    What are the recommended plugs for FZR 3LN1 model? How is it to use iridium plugs, and which ones?
     
    robustus0007, Jan 19, 2011
    #1
  2. Efzedaah

    Efzedaah New Member

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    NGK CR8E plugs I believe. It is in one of the spec sheets available as a pdf file elsewhere here <!-- s:wink: --><img src="{SMILIES_PATH}/icon_wink.gif" alt=":wink:" title="Wink" /><!-- s:wink: -->

    Chris
     
    Efzedaah, Jan 19, 2011
    #2
  3. dave

    dave Well-Known Member

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    Buy them from an auto shop like Repco, Bursons Autobarn etc.. Bike shops charge 4x as much
     
    dave, Jan 19, 2011
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  4. robustus0007

    robustus0007 New Member

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    I currently have four C7HSA plugs installed onto the bike. This plug actually comes for a local 70cc single cylinder bike and the same plugs were there when I bought the bike from its previous owner. Now I heard that the recommended plug for FZR250 is CR8E. I checked in the local market and came to know that a Suzuki GS150 bike here in the market also runs on this plug.

    Below I am posting a pic of both the plugs, as you can see the C7HSA plug has got a smaller head length as compared to that of CR8E. If I put CR8E plug on the bike, will not the cylinder heads actually hit the plug head? With this C7HSA plug, my bike runs good and starts good except in the winter season. I do not tight the plug too much because if I tight it to the full the bike gives starting problems, I always assumed that perhaps its because the plug head gets too neat to the cylinder head. If that be the case, then I am wondering what will be the result if I install CR8E plug on the bike since its head is even bigger in length.

    CR8E Plug
    [​IMG]

    C7HSA Plug
    [​IMG]
     
    robustus0007, Jan 20, 2011
    #4
  5. Charlie1

    Charlie1 New Member

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    give it a try only about 20 bucks
     
    Charlie1, Jan 20, 2011
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  6. dave

    dave Well-Known Member

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    The correct plug is the CR8E. The other is as you say 1/4" shorter and has a different heat rating. You will be losing some compression and also the spark is not occurring in the designed spot in the combustion chamber.

    Try the correct plug.
     
    dave, Jan 20, 2011
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  7. robustus0007

    robustus0007 New Member

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    Ok I'll give it a try. But why do I get starting problem if I tight the C7HSA plug too much? I thought that it happens because the plug gets too close to the piston head, but as compared to CR8E its much shorter and which means that I was wrong to assume that it was getting close to piston head. So what might be the cause?
     
    robustus0007, Jan 20, 2011
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  8. dontz125

    dontz125 Active Member

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    I can't think of a single reason why running a shorter plug "loose" would improve performance. If however one of those shorter plugs was cracked / otherwise damaged, then tightening it could cause problems.
     
    dontz125, Jan 20, 2011
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  9. robustus0007

    robustus0007 New Member

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    Actually the plugs are ok and in fact I put in brand new ones only about a week ago. <!-- s:Help: --><img src="{SMILIES_PATH}/icon_question.gif" alt=":Help:" title="Help" /><!-- s:Help: -->
     
    robustus0007, Jan 22, 2011
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