I'm running a 650 double pumper and having issues with it. I just had the timing set by a mechanic I trust so I don't think that it is a timing problem. The car will pull hard off the line, and up to about 3600-4100 rpm. However, once it reaches that point it sort of hits a wall. The best way I can explain it is the car feels suddenly like its pulling a couple thousand pound trailer behind it, just bogs down. This is pretty much only at WOT. It will sit in the 3600-4100 range and bog for a while, and then it will backfire once or twice. After it backfires, it will pull hard like it should, and I can rev it up into the 5500 range. Any ideas on how I can fix this? Keep in mind I've never tore into a carb before, so try not to confuse me too badly lol.

 

Distributor / Ignition issue ???

Check the plugs 1st

 

Well, I had previously thought that but I just had the timing done and figured it was not the source of the problem.

 

Is the choke shutting? Bowl running out of fuel? Might check the fuel pressure.

 

What is your timing set to?? Do you have approx 34-36 deg's of total mechanical @ 3500 rpm!! Is your fuel pump operating correctly. Does it smoke at that rpm when it bogs down??

 

Yep, Sounds like you are running out of fuel to me.

 

I don't have a choke. Fuel pressure is a good thought, I had wondered about that earlier. I have no idea what the timing is set at, but I trust that my mechanic did it right. I asked someone else about it and they said possibly valve float? That would make some sense I guess, because the valve springs are probably the original. I'm not near my car today so I cant go out and drive it and try to listen to it more closely.

 

I would see what your timing is, there are alot of people who think they know OLdsmobiles, but treat them like Chevrolets!! If he set your timing to spec then it won't run right. Also if your advance plate is hanging up it won't run right! Lets deal with facts and not speculation!!