Stumped. It's gotta be something simple.

[geezer101]

After watching a number of bench tests and looking at your set up, I think you should at least remove the pressure regulator. It's already getting hardly any fuel. Thing to note in vid #1 after revving the engine, it stumbles at the 1 minute mark. At the end of the vid, idle speed goes up to 1,000 rpm and it starts to run erratically like it's leaning out. The initial idle speed is not bad for an engine at operating temp. As vid #2 shows that it's not dumping fuel but only shows signs of some blowback into the carb (in the primary throat side? could only mean open throttle). A simple test to determine if it's fuel deprivation - start it and open the throttle up and observe. If it starts to stumble and tries to stall out, I'll put money on the main culprit being not enough fuel.

[87junker]

After watching a number of bench tests and looking at your set up, I think you should at least remove the pressure regulator. It's already getting hardly any fuel. Thing to note in vid #1 after revving the engine, it stumbles at the 1 minute mark. At the end of the vid, idle speed goes up to 1,000 rpm and it starts to run erratically like it's leaning out. The initial idle speed is not bad for an engine at operating temp. As vid #2 shows that it's not dumping fuel but only shows signs of some blowback into the carb (in the primary throat side? could only mean open throttle). A simple test to determine if it's fuel deprivation - start it and open the throttle up and observe. If it starts to stumble and tries to stall out, I'll put money on the main culprit being not enough fuel.

Once the timing was set correctly I had to adjust the idle back down to 800 but it was alot worse on the primary side before I cleaned it up. It could use some more tlc on the cleaning. But I was wondering about the idle slowly rising as it ran.