edelbrock thunder series avs carb tuning question

[orygunbou71]

Hey all I'm getting a bog/stumble when my secondaries kick in. I want to adjust the secondary butterfly. Which way should i turn the adjustment screw to adjust for the bog/stumble. Its running too lean when the secondaries kick in.

 

[broncnaz]

You should probably download a manual off Edelbrcoks site. But to answer your question turn the screw CCW to make the secondaries come in later. Basically you want more spring tension on the air valve.

 

[pa69broncoguy]

I had the same problem with my evs, they honestly didnt seem to mention the avs at all as part of the tuning. I got disgusted and decided to change over to efi. sorry not much help. Possibly give their tech line a call.

 

[DirtDonk]

Wouldn't a bog be a result of EITHER them opening up too soon, OR too late?
Getting too little air through when wide open could do it I would think, as well as getting too much for the engine/load.

At least that's how I view it on the surface. Not sure of all the variables, and obviously can't feel the bog from here, but I wanted to ask about that. Never tuned an AVS, and always had to rely on the weights being correct on the flapper.

What other specs on your engine orygun? Stock? Big cam? Anything worth mentioning?

Paul

 

[orygunbou71]

Wouldn't a bog be a result of EITHER them opening up too soon, OR too late?
Getting too little air through when wide open could do it I would think, as well as getting too much for the engine/load.

At least that's how I view it on the surface. Not sure of all the variables, and obviously can't feel the bog from here, but I wanted to ask about that. Never tuned an AVS, and always had to rely on the weights being correct on the flapper.

What other specs on your engine orygun? Stock? Big cam? Anything worth mentioning?

Paul

Ford racing 5.0l/302 306ci crate engine with e303 camshaft .498 lift intake, exhaust and duration at .050" is 220 degrees intake and exhaust, full hydraulic roller 1.60:1 ratio. 340hp 350 ft/lbs torque. Edelbrock thunder avs 650 carb on edelbrock air gap 2 intake, edelbrock mechanical fuel pump. 9.0:1 compression. Ford racing aluminum heads 1.94" intake and 1.54" exhaust.

 

[broncnaz]

Secondaries opening to late is a little different as the engine will still have power but wont rev past a certain point like a flat spot. Vs secondaries opening to soon and the engine just bogs and loses power.

AVS adjustements are mentioned in the owners manual.