Results 1 to 3 of 3

Thread: Fuel Spewing Out Breather Tube

  1. #1
    ratonabike Guest

    Default Fuel Spewing Out Breather Tube

    I have an HP4150 750 carb, and under certain circumstances, after running for a bit, then from on the throttle to then idling, fuel will sometimes spew out of my primary breather tube, stalling the engine. This situation occurred after rebuilding my carb for the first time awhile back, but with both breather tubes, and I found that readjusting my float levels (with little room left on my adjusters), the problem seemed to go away, but has since resurfaced on my primary breather tube. This is not fun as it stalls my car when I'm in traffic in the most inopportune time, and creates a bit of a fire hazard with fuel pouring out. Any ideas what my problem is? I'm pretty new to Holley carbs. thanks!

    Note I'm running 6-7psi from a mechanical pump, on a 406ci SBC.

  2. #2
    Join Date
    Dec 2009


    Seems like the 'needle & seat' assembly isn't quite sealing when closed. Or the float level is set too high.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: Dominator MPFI & DIS, A/C, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/X-pipe/shorty headers, 100HP progressive dry direct-port NOS, 160A 3G alternator, Optima Red battery, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

  3. #3


    lower the floats at least 4 flats, have you examined the needle valve closely, might be some trash on it.

    Last edited by zray; 06-11-2010 at 12:15 AM.

    '66 GT-350 Original Drivetrain, Sheet-Metal, Interior, & Paint

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