Im in the process of tuning my holley 600 to my 318. it seems to be leaning out during mid range acceleration and also a little lean off idle. anyone know what could be the problem? im not an expert on holleys. thanks
-kevin

Mid range exceleration and lean off idle both point towards the accel pump adjustment. Double check your accel pump with the engine running to see if you have a squirt of fuel as soon as you hit the carb linkage. If your pump is setup correctly, then try a larger squirter.

Note: check your float levels too.

If the issue still exists, then raise the size of your primary jets.

You can become an expert (sort of.):

Holley.comTech Service Information



Lots of great Free advice and videos, troubleshooting information, setup info, etc,
Also these FAQ's:

Holley FAQ's

Which Holley carb? I think the street avenger carbs are tuned a bit lean. Usually the idle and power valve restrictions are smaller than the performance carbs.

Increase the front jets one or two sizes.
Set the float too, if it is low dothat first before the jets.

make sure your power valve matches the requirements of your engine based on vacuum at those moments you describe when it seems to be lean.

I know the float level is set right, but Ill have to check in on those other possibilities later. thanks!
-kevin

btw, I pulled a spark plug after a little drive and it came out fairly white. Ill change the jets and see what happens.