Holley 770 Questions

[Mattsvtcobra]

Originally Posted by MaSnaka

Matt do you have a cable or linkage connecting the pedal to the carb?? When you say you lift the pedal and the RPM goes down sounds like there is a bind somewhere between the two. Then you say you can tell by start up whether it will run good or have the RPM hang up. Vac advance on the dist? Vac leak possible or bad diaphram?? The air cleaner should not be resting on the dist. I have the oval Cobra air cleaner and it clears my dist by about a 1/4" from the side but is nowhere near sitting on top. I have the FE motor which might make a difference. Does the air cleaner contact the choke horn?? Could cause air flow restriction on acceleration. Trying to think outside the box.

John

Do you have a cable or linkage connecting the pedal to the carb?? When you say you lift the pedal and the RPM goes down sounds like there is a bind somewhere between the two.
--- It's weird, it seems to happen once the engine has warmed up. So something is changing when heat becomes a factor. That's why I wasn't sure if the carb had something that needed to be checked or lubed. Can a lubricant just be sprayed where I see levers moving and also down the throttle cable?

Then you say you can tell by start up whether it will run good or have the RPM hang up. Vac advance on the dist? Vac leak possible or bad diaphram??
---No vac advance

The air cleaner should not be resting on the dist. I have the oval Cobra air cleaner and it clears my dist by about a 1/4" from the side but is nowhere near sitting on top. I have the FE motor which might make a difference. Does the air cleaner contact the choke horn?? Could cause air flow restriction on acceleration.
---Mine does not clear. Not sure what you mean by the choke horn?


Trying to think outside the box.
--- I really appreciate it!

[MaSnaka]

Hi Matt,
I use the silicone spray and lube the external moving parts on the carb with it on occasion, really not very often.

Air cleaner and choke horn- choke horn is the shroud surrounding the choke plates on the top of the carb. Rises about 1 1/2" above the carb opening. Some air cleaners being low profile to fit under the cobra hood, the inside of the air cleaner top is either making contact with the choke horn or very close to it. This can restrict air flow into the carb as you approach wot when the engine is sucking in the most air.

Do you have a phenolic spacer between the carb and the intake manifold? This insulates the carb from heat which might be causing some deflection in your linkages. I have only heard of them being used to prevent the fuel from boiling in the carb but maybe.

John