Been fighting an issue since last fall. Let it rest over winter. My HS6 on my '68 B18B were worn at the shafts. I picked up a set of HIF6 from an early '70s B20. Got another combo manifold with buterflies as my manifold looked to have been repaired before.

Rebuilt the HIF6s with care. Double checked float level. New shaft seals. New manifold gasket. Let secondary butterflies in. Very hard starting after lots cranks. Idled but could not drive. Tried setting the jets richer. Pulled HIF6s. Saw nothing. Replaced manifold with combo that has no secondaries. Plugged all vacumn lines. Still lots cranks and then it would start. Ran the same. Changed fuel pump. Tested flow into can. Seemed ok. Put fuel pump input into gas can. No better. Even tried to gravity feed the carbs.

I tested the compression cold. All tested about 155. Wet test raised a bit but not much. Checked valve clearance as well.

I dribbled a small amount of fuel into each carb. Soon as I hit the key it fires right up. Then dies. Seems like a lack of fuel. Gas seems to be getting to the carbs but not through them. At a loss what to try. I have read that the HIF6 might not be a great match for the B18 and often required a rejet to get running right. If so I'm sureprised it will not even start and at least idle. If I recall the HIF6 have the BBB needles now.

Craig