Author Topic: Edelbrock Quadrajet 1904 Throttle shaft size  (Read 1457 times)

Offline sbc357-75camaro

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Edelbrock Quadrajet 1904 Throttle shaft size
« on: May 22, 2023, 10:35:33 PM »
Hello Cliff and all,
                 I want to purchase a throttle shaft bushing kit for my Edelbrock Quadrajet 1904, but I don't know what size throttle shaft  came on this unit. Would you or anyone know if it's the 3/8" or 5/16"  that I need? Any information would be appreciated. Carb works perfectly all the way around, except for one issue: idle speed fluctuation. There's about 200 RPM of play with the idle speed; I set it at 800 in park, but sometimes it goes down to 700 RPM, other times it'll settle at 900 RPM. It doesn't wander up and down,  it just seems to settle at a different RPM every time I check it in neutral at a red light, or when I'm in Park. If I adjust the screw, it doesn't respond as I turn it. I have to flick the throttle to see my adjustment take effect. I'm thinking that installing the throttle shaft bushing kit may cure this problem, as I think my throttle shaft may be worn. Any advice on what size these Edy Quad's throttle shafts were would be greatly appreciated! Thanks all, -JT

Offline Kenth

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Re: Edelbrock Quadrajet 1904 Throttle shaft size
« Reply #1 on: May 23, 2023, 01:00:06 AM »
If it really needs the bushings they are 5/16". Cliff got the parts/kit.

But, i would first verify the timing and distributor weights and springs. If they are too light aftermarket junk, coming in too soon, this would more likely be your problem.