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Discussion Starter #1
I've been slowly playing with the tune for a while now and I have two issues. The engine is a stock ZZ4 and the carb is a Holley 80508 750 Vac

1. The throttle linkage seems to stick. It acts like the fast idle is engaging. I can tap the throttle and slow it down. It will idle as high as 2500 RPM. It will pull 40 mph in 5th. I have a Locar cable, bracket and double spring on it. Do I just need more spring? Some times it is worse than others, but it is a pain tapping the gas to slow it down.

2. I still have a small stumble at low speed. It doesn't do it when it is cold, only warm. I have the initial timing set at 15 or 16 degrees. I've also put a a #35 squirter and a lighter secondary spring. It has gotten better, but it is still there. Any ideas?
 

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be sure the float levels are correct. are you running vacuum advance? how much vacuum is the engine pulling? you may try changing the accel pump cam with a bigger one that delivers a longer stronger shot. As far as the throttle sticking does it stick with the cable disconnected? is the choke linkage move freely?
 

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Discussion Starter #3
be sure the float levels are correct. are you running vacuum advance? how much vacuum is the engine pulling? you may try changing the accel pump cam with a bigger one that delivers a longer stronger shot. As far as the throttle sticking does it stick with the cable disconnected? is the choke linkage move freely?
The choke linkage does move freely. I've haven't tried disconnecting the linkage, but I am able to push to idle with my finger. Sometimes it will gradually slow down on its own
 

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do you have an open carb gasket? sometimes I've seen people use the 4 hole gasket and it hangs up on the throttle blades.
 

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Discussion Starter #5
do you have an open carb gasket? sometimes I've seen people use the 4 hole gasket and it hangs up on the throttle blades.
It is a 1/4 inch thick Holley 4 hole gasket. I'll have to look at it.
 
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