I have a Holley Marine 800 DP on my stock Gen V 502. Just as I am staring to get into the secondaries at about 4000 rpms it starts buzzing under the engine hatch. If I push the throttle through this it goes away and is fine all the way to WOT. I have heard that Holleys sometimes lean out just as the secondaries start to open. Overall, I think my jetting is OK. I have done plug checks at half throttle and at WOT. I have also overrichened the jetting and then backed down until it ran good. I have heard that Holleys somtimes lean out just as the secondaries start to open. Is the a way to cure this?

ttt

Sounds like you need to look at intermediate circut in the carburetor with screw in air bleeds. Ask for some references on a good carb shop.

Thanks jspeeddemon. I knew someone on here would give me a clue as to where to start. I guess this is not a common problem or others would have replied.

See ya, Doug