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intermitten idle surge
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DRR Sportsman
Picture of Mike Frizie
posted
verified both the front and rear butterfly shafts and cable aren't sticking on new carb. but sometimes when you rap the throttle the idle stays high, then you kick it once or twice it returns to normal. don't see anything holding it open. thoughts??


Michael Frizie
ET 2471
 
Posts: 571 | Location: Winston, GA | Registered: April 10, 2002Reply With QuoteReport This Post
DRR Pro
Picture of Bruce Williams
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I have had the secondary throttle shaft spring not be strong enough to close the secondaries from a part throttle "rap"
I installed a small return spring to the secondaries to eliminate the problem.


Bruce Lee Cool

Experience is what you get when you don't get what you want.
 
Posts: 2033 | Location: Chandler Arizona | Registered: August 11, 2005Reply With QuoteReport This Post
DRR Sportsman
Picture of Ron Gusack
posted Hide Post
I had the same issue with a 4500 that was just barely sticking.
 
Posts: 459 | Location: Maryland | Registered: January 23, 2007Reply With QuoteReport This Post
DRR Pro
Picture of rusty
posted Hide Post
squirter cams can be dry and cause some issues


honesty is the best policy,insanity is a better deffense
1.036, 6.16@ 224

 
Posts: 1408 | Location: texas | Registered: February 17, 2006Reply With QuoteReport This Post
DRR Trophy
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I have the same thing happening on a new apd. I can't tell why it stays open. My rear blades are barely staying open.
 
Posts: 24 | Location: Roxboro NC | Registered: May 09, 2002Reply With QuoteReport This Post
DRR Trophy
Picture of NC3x58
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I've noticed my Primary butterfly won't return all the way back to idle and do this sometimes. I haven't really looked into what it could be, but likely just needs a little lube on the mechanism is my guess.


Nick Craig

1971 Camaro Split Bumper
376ci LS3
 
Posts: 410 | Location: Ohio | Registered: December 28, 2013Reply With QuoteReport This Post
DRR Top Comp
Picture of Curly1
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Check your throttle from pedal to carb. Make sure it is clean and not binding any where. On my stuff I like several return springs and I like it fairly stiff. But you do not want all of those springs on the carb or it will wear out and bind the shafts. If your cable is on top and spring is on bottom (or Vice-Versa) then both are pulling against the shaft and that is hard on it and will cause problems. If possible you want the return spring and cable mounted inline at same place on carb to reduce the stress on it. Then it will rotate and return easy and shafts will last much longer. A good throttle and return spring design is important and I see a lot f them of poor design and some are rather expensive big name junk.


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Posts: 3999 | Location: United States of Texas | Registered: April 02, 2011Reply With QuoteReport This Post



DRR Sportsman
Picture of Mike Frizie
posted Hide Post
new apd here also. ive pressed on anything and everything when is racing. nothing feels likes it off its resting spot. weird. just kick it once or twice fine. two springs at the pedal, and a moroso bracket at the carb linkage with two light springs.


Michael Frizie
ET 2471
 
Posts: 571 | Location: Winston, GA | Registered: April 10, 2002Reply With QuoteReport This Post
DRR Pro
Picture of Brktracer
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Working in some WD40 to the throttle shaft has solved that on multiple carbs I've worked on. Usually the secondary is not closing completely.


Matt Ward



 
Posts: 1389 | Location: South Carolina | Registered: March 20, 2004Reply With QuoteReport This Post
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