I've cleaned the jets. I've checked for vacuum leaks. I've twisted the nut for the accelerator pump all the way in and all the way out, and no sweet spots were found in between. Try as I may, whenever I press on the gas, if not done verrrrry gradually, it tries to die. I've searched the forum. It's getting plenty of fuel to the carb, there's no clogs. I can see the accelerator jets and the main jets shoot fuel when I press it down, but nothing. It always wants to die. I can keep it going, but it's a serious pain. I've disconnected and plugged off every vacuum source. I removed the air pump and blocked it off, sealed it quite well. I simply can't think of what else to check here.

 

bump

 

the symptoms you describe are those of a faulty accelerator pump. If the diaphragm is old, it tends to get brittle and won't squirt that good anymore. It might even leak. Check it out.

 

Possibly your problem. One other thing is the pump shot timing. That nut should be adjusted so the pump squirts as soon as the linkages move. Any delay will result in a stumble/hesitation. Ive also recieved carbs where the checkballs/checkweights were missing which would cause a weak or no pump shot.

 

I have a similar problem. When i start mine it idles high (5k-6k) then it will go down to around 2k every now and then but when i give it gas it cuts out. And ive cleaned everything in my carb and it was rebuilt recently and it floods bad.

 

The diaphragm looks good...I took it all apart again and started from scratch. It's much better now, just need to adjust the timing of the shot and it should be fine. Now the weird oil problem...