[Hurst65]

Originally Posted by Schurkey

What happens if the idle speed is more reasonable? 900 is kinda high.

Is that 11" of vacuum at idle the most the engine will make at that throttle position? Does changing the idle mixture screws increase the vacuum from there?

Great question. Okay, so I wanted to see the same thing. Here's what I found out--
1.) I can go down to 750 RPM but, the engine doesn't seem to like it. It kinda starts to lug and it's just not very smooth. I brought it up to 800 RPM and that seems like a good compromise.

2.) I was able to eek out about 12" of vacuum after some further tinkering. Not a big change in vac. readings.... maybe + or - 1" of vacuum either way with the screws. But a tiny turn of the screws, one way or the other, really makes a big difference on the wideband gauge.

I opened up all 3 carbs this afternoon to verify my baseline.

Center carb - Idle tubes are at .0355", .066 Jets (waaaayy toooo fat!)
End carbs - .072 Jets

I switched the end carb jets to .070 while I had them open.
I was going to put smaller jets in the center but, I don't have any. I'll have to order some. I'm not sure where to start, thou. I'm thinking .063's. ??

Overall, I think I'm going in the right direction. I just need to get some smaller jets for the center carb and go from there.