Results 1 to 2 of 2

Thread: 4272 I think it is a spark issue?

  1. #1
    Daveyboy Guest

    Default 4272 I think it is a spark issue?

    I need some advice. I have the p/n:4272 on a yamaha super jet. It appears that I have spark with no load and that is by grounding the plugs and turning over the motor. It idles fine when running, but bogs when you rev it up. One spark plug looks like it's new and wet looking as if there is no spark. (started with fresh plugs). It seems to me that there is a lack of spark when it's under load. Can this occur? What can i do to test it if possible?

    Thanks in advance,


  2. #2


    Have you tried false triggering the ignition to see if both spark plugs are firing at the same time? The 4272 unit is a wasted spark system which means it will fire the spark plugs at the same time. If you still have a weak spark on one of the spark plugs it could be a bad coil please let me know which coil you have so I can get you the coil specs. Have you checked your battery to make sure it’s supplying the proper amount of voltage to the unit?

    Here is my email address to make it a little easier

    Thank you


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us