|
Holley carbutretor question
I have a 700 holley double pumper on a 351w. Can't get it to idle down. Secondary throttle plates don't close all the way. At idle I can cover the primaries with my hand and it still runs. Cover the secondaries and it quits. Set screw for the secondaries is backed off so its not that. Is it worth a rebuild or is their an easy fix? Should I just replace it with a 670 Holley Street Avenger? Thanks Jim
|
Jim,
You didn't say whether you had a vacuum or mechanical secondary. If you have vacuum you may have too weak of a Diaphragm spring. The spring controls the opening rate of the secondaries and there are different spring rates available (a weak spring will allow the secondaries to open early). Holley has quite a bit of information available on their web site (www,holley.com) in the Tech section regarding setup and troubleshooting. You can also call direct to Holley and speak to a tech the PH#. is on the site. Be sure you have your carb model # (located on the choke horn in front of the primaries. good luck, Mike "monster" |
Also have 700 Holley DP (#4778) on 351W.
Sounds like engine is running mostly on open secondaries, and you need to find out what is holding them open. The only thing that is supposed to be holding them open is that set screw. The only thing I can think of is binding in the throttle shaft, or the throttle blades in the bore. You may have to loosen the throttle blade screws and relieve any binding in the bore. I have a hydraulic roller cam which pulls 15" - 16" vacuum at idle. To lean it out, I jetted the primaries back to 64. Set the primary throttle blades under the transfer slot, then set the idle speed with the secondaries. Replace the secondary set screw with an allen set screw (10-32), and you can now adjust it on the car with engine running. |
Got it fixed. Throttle blades were not centered in the bores. Jim
|
| All times are GMT -7. The time now is 02:56 PM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: