Quote:
Originally Posted by Sieg
Back to business..........
I fiddled with the fuel screws and throttle positions and obtained near 12" vacuum at 1K rpm which is as good as it gets with this cam IMO.
Throttle response right off idle felt good actuating it by hand. The initial timing was 13-14* with 21* mechanical. I decided to experiment with initial timing and see how the motor would respond. I bumped it to 15-16* and immediately had a big flat spot right off idle. WTF? Dropped it to 12-13* and still had the flat spot. Put it back to 13-14* and the flat spot was still there......I managed to create a flat spot without touching the carb settings, just changing the initial advance. 
I list timing as 12-13*, 13-14*, 15-16* because that's what it is when locked down.
I've had subtle doubts since this motor went back together...........something hasn't seemed quite right and this latest issue is supporting my suspicions.
Gear drive or distributor possibly creating issues? |
Did the engine temperature change? That amount of timing shouldn't make much difference to a bog. You aren't going to tune out a stumble with idle mixutre and transfer slot. It's time to start playing with accel pump cams.