Discussion in 'Photos & Bicycle Builds' started by TheWizard, Apr 18, 2015.

  1. TheWizard

    TheWizard Member

    New 5.5 cc competition center fire Fred head

    40 tooth CNC sprocket

    The NGk spark plug we are originally running is to the right and the new NGK spark plug thats required for the Fed head is to the left a lot smaller.

    Will be posting pictures of the final look stay tuned :cool:


  2. butre

    butre Well-Known Member

    you might need race gas with that head, or a few extra gaskets
  3. jaguar

    jaguar Well-Known Member

    you need to retard the ignition more when you increase compression because higher compression causes the fuel mixture to burn more rapidly.
  4. TheWizard

    TheWizard Member

    What do you mean by Retard the ignition? We did get better performance but we are getting 4 stroking at high rpms. I feel like I can get more power, but I'm getting the four stroking. I am going for a long ride today, and then going to check my spark plug to see what's going on. Any suggestions or tips? Thanks!!!
  5. jaguar

    jaguar Well-Known Member

    retarding the ignition is making it happen later.
    most motorcycles have stator coil plates that allow you to retard or advance the ignition, but not this engine. You have to replace the ignition system (all but the stator coil and spark plug).
    click on my signature link and read, read, read
  6. TheWizard

    TheWizard Member

    IMG_0482.jpg View attachment 56992 We have been looking into changing the ignition system. Looks like we are going to now, hopefully we can see the performance gain we were hoping to get. Thanks Jaguar for pointing me to all that great information. I finally got around to installing my SBP expansion chamber. Unfortunately, the only way to install it was from the top. Not the way I envisioned it. Wrapped it with some nylon to protect myself from burning my left leg (Nylon wrap was difficult to wrap near the baffle section) and also because it just looks sick! I like the way this expansion pipe works because I have better take off speed, but I am not a huge fan of the noise. To me...it is to quiet. The popping noise is great, but not loud enough compared to my last pipe. My last pipe had a popping with a grumbling sound and it was loud. I will trade sound for a better performing bike, and the SBP pipe looks cooler. I can figure out how to modify the pipe for sound later. Here is picture of how it came out.
    View attachment 56989
    Last edited: Apr 20, 2015