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Author Topic:   4412 adjustments
Dirt Freak

Total posts: 243
posted April 23, 2005 11:22 AM  
what is the proper acc. pump adjustment for a holley 4412, its got the 50cc pump. someone told me that at idle its supposed to have a lil clearance between the pump arm and the throttle linkage? we tried that and the engine will not hardly start and pops at idle and when you rev it up so we put it back where it was (at idle the pump arm was actually pushed down a lil) weve got the float level set and used a vacuum gauge to set the idle mixture screws but i dont know the adjusment on the acc. pump any help would be greatly appreciated

[This message has been edited by bryanb30 (edited April 23, 2005).]

Dirt Freak

Total posts: 243
posted April 24, 2005 08:19 PM  
ok guys maybe i worded it wrong!! where on this internet thingy can i go read stuff about fine tuning holley carbs!!

redneck racing
Dirt Forum Champ
Total posts: 860
posted April 25, 2005 01:29 AM  
Try see if this helps. Eddie

Dirt Forum Champ
Total posts: 626
posted April 25, 2005 01:45 PM buy his cd.

Dirt Maniac

Total posts: 137
posted April 25, 2005 03:59 PM  
the accel pump arm should just have a little bit of free play in it, if you dont and set it like you are the pump still works exactly the same but cant fill up entirely becuase youve allready got it compressed some.

Adjusting that arm like you did could not possibly effect your motor at idle, it only works when you accelerate and gives you a bunch of fuel out the squirters to prevent it going lean until the jets catch up.

youve got other issues if your car wont idle, popping at idle is usually a valve adjustment problem on my motors, and or timing is retarded, or not advanced enough.

Dirt Forum Racer

Total posts: 100
posted April 26, 2005 05:10 PM  
Holley states the pump arm should be set at .015" clearance.


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